Discussion Board
Current Forum: exam 1 questions examples Read 82 times
Date: Mon Oct 6 2003 2:34 pm
Author: Almond, Janice <jsaz7c@studentmail.umsl.edu>
Subject: test
test
Current Forum: exam 1 questions examples Read 81 times
Date: Mon Oct 6 2003 2:35 pm
Author: Gagnon, Lawrence <ljgbp3@studentmail.umsl.edu>
Subject: Stats
Can you read this?
Current Forum: exam 1 questions examples Read 163 times
Date: Mon Oct 6 2003 2:37 pm
Author: Owen, Scott <shoyq9@studentmail.umsl.edu>
Subject: User Questions
Place your questions here with Reply
Current Forum: exam 1 questions examples Read 80 times
Date: Mon Oct 6 2003 2:44 pm
Author: Floyd, Mary <mkf5ff@studentmail.umsl.edu>
Subject: Re: User Questions
1. The normal distribution is a
a. discrete distribution*****
b. continuous distribution
c. positively skewed distribution
d. none of the above
2. Which of the following are correct statements about a normal distribution?
a. It is a symmetric distribution
b. It is bell-shaped
c. It is asymptotic
d. All of the above*****
3. In a normal distribution the relationship between the mean, median,
and the mode is:
a. They are all equal****
b. The mean is the largest
c. The median is the largest
d. None of the above
e. All of the above
Current Forum: exam 1 questions examples Read 48 times
Date: Mon Oct 6 2003 4:37 pm
Author: McSpadden, Ryan <ram2m9@studentmail.umsl.edu>
Subject: sample questions
1. A certain manufacturer makes a playground ball with a normally distributed
mean of 6 inches and a standard deviation of 0.4 inches. What is the probability
of finding a diameter less than 4.8?
a 0.13%
b 1.3%*
c 99.87%
d -3
e 3
2. By increasing the alpha level which will result?
a change in the mean
b increase in the beta level
c it is more likely that the null hypothesis will be rejected*
d all of the above
e cannot be determined
3. A increase in the observed mean will result in?
a a decrease in the standard deviation
b an increase in the standard deviation
c a increase in the hypothesized mean
d a decrease in the hypothesized mean
e none of the above*
Current Forum: exam 1 questions examples Read 66 times
Date: Mon Oct 6 2003 6:54 pm
Author: Schneider, Claire <cms39e@studentmail.umsl.edu>
Subject: Re: User Questions
1) The Central Limit Theorem is Powerful because
a)*** it works for any population distribution provided the sample
size is sufficiently large
b)it works for any sample size provided the population is normal
c)it works for any population distribution provided the distribution
provided the population mean is known
d) because it works out a lot :)
2)If you have a mean equal to 90 and a Confidence level (95%) equal
to 21.5,
2A)what is your lower limit?
a)111.5
b)68.5****
c)4.186
d)95
2B) What is your upper limit?
a)111.5****
b)68.5
c)4.186
d)95
3)How do we know what kind of T-test to use in exel?
a) by calculating the lower and upper limits
b) trial and error
c) conducting an F test *****
d) if the means, we dont have to use a t-test
Current Forum: exam 1 questions examples Read 62 times
Date: Mon Oct 6 2003 9:27 pm
Author: Estes, Kimberly <klehw2@studentmail.umsl.edu>
Subject: Re: User Questions
1)What test do you use to compare two variances?
A. t-test
B. z-test
C. f-test***
D. 2 z-test
E. Histogram
2)Which of these are needed to calculate p-value in a t-test?
A. df
B. hypothesized mean
C. standard deviation
D. number of tails in the test
E. observed sample mean
F. all of the above***
3)How do you parse data?
A. data, text to column***
B. tools, add-ins, data analysis, text to columns
C. right click, text to columns
D. edit, columns
E. none of the above
Current Forum: exam 1 questions examples Read 62 times
Date: Mon Oct 6 2003 11:41 pm
Author: Palmer, Lisa <lmpry6@studentmail.umsl.edu>
Subject: Re: User Questions
An orange company has determined that the diameter of their oranges
are normally distributed with a mean of 3.2 inches and a standard deviation
of 0.4 inches. What is the probability of finding an orange with a diameter
between 3.8 and 4.2 inches?
a. 2.3%
b. 8.9%
c. 6.8%
d. less than 1%
e. 5.5%
The z value for a 97% confidence interval is
a. 1.88
b. 1.96
c. 2.00
d. 2.17
e. 2.67
An estimate of a population parameter that provides an interval of values believed to contain the value of the parameter is known as the
a. confidence level
b. interval estimate
c. parameter value
d. population estimate
e. sample size
Current Forum: exam 1 questions examples Read 48 times
Date: Tue Oct 7 2003 12:42 pm
Author: Almond, Janice <jsaz7c@studentmail.umsl.edu>
Subject: Put Your Answers w/ questions!!!
.
Current Forum: exam 1 questions examples Read 45 times
Date: Tue Oct 7 2003 3:15 pm
Author: Moore, Sara <sbmwt2@studentmail.umsl.edu>
Subject: Questions w/ Answers!
1) The purpose of the critical value is: (B)
a) to determine the mean
b) to seperate the rejection region from the non
rejection region
c) helps you find the z-score
d) determines the sample size
e) none of the above
2) When looking at a problem, what is important? (E)
a) determining what is the parameter
b) knowing whether you have a large or a small sample
c) knowing what kind of test we are going to perform (ex.
t-test, f-test, etc.)
d) knowing whether you have a 1-tail or 2-tail test
e) all of the above
3) Why would you choose to do a t-test rather than a z-test? (A)
a) because you have a small sample
b) it really doesn't matter which test you choose
c) it depends on your confidence level
d) your probability is too small
e) none of the above
Current Forum: exam 1 questions examples Read 54 times
Date: Tue Oct 7 2003 5:00 pm
Author: Dooley, Sean <smd7b6@studentmail.umsl.edu>
Subject: Re: User Questions
Which will be accepted only if the data provide convincing evidence
of its truth?
A. Ho
**B. Ha
C. t statistic
D. z score
E. f test
A sample of 100 observations was taken from a population with a mean=33 and standard deviation=20. A corresponding sample has a Xbar=29. What is the probability of getting a sample of size n=100 with the mean=29 or lower?
A. 5%
B. 10%
**C. 2%
D. 8%
E. 15%
Deciding that the null hypothesis is false when in fact it is true is referred to as a:
A. test statistic
B. rejection region
C. type II error
**D. type I error
E. one tailed statistical test
Current Forum: exam 1 questions examples Read 46 times
Date: Tue Oct 7 2003 5:20 pm
Author: Dilthey, Jeffrey <jmd0ae@studentmail.umsl.edu>
Subject: Re: User Questions
1) The t distribution is based on what assumptions?
a) the sample has a normal probability distribution
***b) the population has a normal probability distribution
c) the sample has sample size greater then 25
d) the population has a population size greater then 25
e) the sample was taken at random
2) As the degrees of freedom increases, what happens to the t distribution?
a) it becomes wider
b) it becomes tighter
c) approaches the standard normal distribution
d) I & III
***e) II & III
f) III only
3) In excel functions, which tells you the critical T value?
***a) TINV
b) TDIST
c) STDEV
d) TTEST
e) VAR
Current Forum: exam 1 questions examples Read 59 times
Date: Tue Oct 7 2003 6:49 pm
Author: Mott, Lauren <lnmce0@studentmail.umsl.edu>
Subject: Re: User Questions
1. What is a type II error?
**a.You accept Ho when it is false
b You reject Ho when it is true
c. You apply the wrong alpha
d. When both Ho and Ha are false
2. How do you fing the Upper Limit when using descriptive statistics?
a. Subtract the mean from the confidence interval
***b. Add the mean to the confidence interval
c. Add the mean to the standard deviation
d. Subtract the standard deviation from the sample size
3. When using the p-value when is the test results not significant?
a. if it is greater than .01 but less or equal to .05
***b. if it is greater than .05
c. if greater than .001 but less than or equal to .01
d. less than or equal to .001
Current Forum: exam 1 questions examples Read 41 times
Date: Tue Oct 7 2003 6:59 pm
Author: Konjicija, Davor <dkpm7@studentmail.umsl.edu>
Subject: test questions
For a given hypothesis test,if we do not reject Ho and Ho is true
***no error has been commited
type 1 error has been commited
type 2 error has been commited
type 3 error has been commited
none of the above
In testing the difference between the means of two normally distributed
populations using large independent random samples, the correct test statistic
to use is:
*** Z statistic
t statistic
F statistic
all of the above
none of the above
Type 2 error is defined as the probability of__________Ho,when it should____________
failing to reject, not be rejected
***failing to reject,rejected
rejecting,not be rejected
rejecting,rejected
none of the above
Current Forum: exam 1 questions examples Read 48 times
Date: Tue Oct 7 2003 7:44 pm
Author: Wolff, Travis <tuwvd3@studentmail.umsl.edu>
Subject: Re: User Questions
1) On excel, you use which
statistical function to calculate the critical t-value?
a. T inv *
b. T dist
c. Analysis toolbox
d. St Dev
2) On excel, the bin range
is:
a. The first set of data
on a multi-variable test
b. The number of items that
show up when you do descriptive statistics
c. The number of items appearing
on a histogram
d. A range to classify and
organize the data *
3) What does the F-test test
for?
a. To see if an individual
independent variable is significant
b. To determine whether a
significant relationship exists between dependent variables and the set
of all independent variables*
c. To calculate descriptive
statistics
d. The difference between
two data sets
Current Forum: exam 1 questions examples Read 40 times
Date: Tue Oct 7 2003 7:48 pm
Author: Schaetty, Eric <ems508@studentmail.umsl.edu>
Subject: Re: User Questions
1. If the observed mean for a sample is 4.2, the hypothesized mean
is 0, the standard deviation is 2, and n=100. What is the T value?
**1. 21
2. 14.5
3. 3.3
4. 10
5. None of the above
2. For a given sample we derived descriptive statistics and found the mean to be 3.78, the standard deviation 2.21, and the confidence level to be .86. What the upper and lower limits, respectively?
1. 5.99, 1.57
**2. 4.64, 2.92
3. 6.78, 3.02
4. 7.89, 5.90
5. 2.21, ,86
3. If after doing some testing on given sample we found our P value to be .6789 and we had an alpha of 5%, we could conclude that:
1. the probability of getting the null hypothesis is very good.
2. the probability of rejecting the alternative hypothesis is very
high.
3. there is sufficient evidence to reject the null hypothesis.
**4. there is inadequate evidence to reject the null hypothesis.
5. the chances of this happening again are about 1.789% higher.
Current Forum: exam 1 questions examples Read 45 times
Date: Tue Oct 7 2003 8:52 pm
Author: Becker, Christopher <cmb305@studentmail.umsl.edu>
Subject: Re: User Questions
1. A type I error is always made when:
***a. the null hypothesis is rejected when it is true
b. the null hypothesis is not rejected when it is false
c. the research hypothesis is rejected when it is true
d. the research hypothesis is not rejected when it is false
2. The level of significance is:
***a. the probability of rejecting the null hypothesis when
the null hypothesis is true.
b. the magnitude of the sample size.
c. symbolized by the greek letter BETA.
d. none of the above.
3. A result was said to be statistically significant at the 5%
level. This means:
a. the null hypothesis is probably wrong
***b. the result would be unexpected if the null hypothesis
were true
c. the null hypothesis is probably true
d. none of the above.
Current Forum: exam 1 questions examples Read 43 times
Date: Tue Oct 7 2003 9:11 pm
Author: Boggiano, David <drb71a@studentmail.umsl.edu>
Subject: Re: User Questions
1A. What is the probability of selecting a person whose height is 60
inches? Mean = 55, standard deviation = 5.
a. 6.58%
b. 2.28%
****c. 15.87%
d. 22.26%
e. 17.68
1B. What is the probability of selecting a person who is exactly 60
inches?
a. 26.87
****b. 50.00%
c. 65.00%
d. 46.30%
e. 55.00%
2. A type I error is?
****a. rejecting a true null hypothesis
b. rejecting a false null
hypotheses
c. not rejecting the alternative
hypothesis
d. rejecting the alternative
hypothesis
e. rejecting the null and
alternative hypothesis
3. The formula used to calculate the Upper Limit is?
a. standard deviation plus
confidence level
b. mean minus standard deviation
c. variance plus mean
d. mean minus standard deviation
****e. mean plus confidence level
Current Forum: exam 1 questions examples Read 42 times
Date: Tue Oct 7 2003 11:06 pm
Author: Holbrook, Michael <mlh301@studentmail.umsl.edu>
Subject: Re: User Questions
A recent study claims that on average, college students get more than
7 hours of sleep per night. After staying up all night to study for a stat
test, you decide that this is an overestimate.
(1) Set up the hypotheses for this test.
(2) If you randomly select 40 students and select ƒÑƒn= .01,
what is the rejection region?
(3) Based on your sample, you determine that the mean number of hours
of sleep per night is 5.5 with a standard deviation of 1. Calculate the
test statistic.
(4) What conclusion can be made?
(5) What does the central limit theorem say?
Current Forum: exam 1 questions examples Read 41 times
Date: Tue Oct 7 2003 11:07 pm
Author: Speck, Michael <mrsrn5@studentmail.umsl.edu>
Subject: Re: User Questions
A trained worker in a factory of building chairs, should be able to
assemble a certain type of chair in 15 minutes. Is this figure substantiated
by the carefully timed assembly of 150 randomly selected chairs whose average
assembly time is 15.4 minutes with a standard deviation of 2.4 minutes?
A.we reject the null
B.we accept the null
C.we do not have enough info to make a decision
Answer: A) we have to reject the null hypothesi , because z=2.04 and therefore exceeds the t crit of 1.96
The z value of 1.61 is?
A. .4463
B. .1255
C. .0239
.0199
Answer : A
What is the formula for degrees of freedom of a sample size
A. n
B. n-1
C. the difference of the
means between two samples
Answer B.
Current Forum: exam 1 questions examples Read 39 times
Date: Wed Oct 8 2003 12:15 am
Author: Mason, Benjamin <bbmhwb@studentmail.umsl.edu>
Subject: My very good questions for passing this test
1. What specifically does the f-test tell us?
a. Whether the samples are equal
b. Whether the sample means are equal
c. How large the difference between population means are
d. **Wheter the sample variences are equal
e. What the size of the sample means are with respect to the t distribution
2. What does increasing the sample size do to our hypothesis testing?
a. It makes our p-values smaller
b. **It makes our p-values larger
c. It makes our alpha larger
d. It makes our beta larger
e. It makes our alpha smaller
3. When the null hypothesis is rejected, but is true that is called
a(n)
a. **Type I error
b. Bad guess
c. Aerithmatic error
d. Type II error
e. Sampling error
4. The degrees of freedom are simply
a. How often you can be wrong in hypothesis testing
b. How wrong you can be in hypothesis testing
c. How many minutes past curfew your parents "really" let you sty out
d. The range in which the average of the means falls
e. **The sample size less one
Current Forum: exam 1 questions examples Read 37 times
Date: Wed Oct 8 2003 3:24 am
Author: Merkel, Pamela <pkmkt3@studentmail.umsl.edu>
Subject: Re: User Questions
1. If the mean is 130, sd = 10
What is the probability of finding a randomly selected female that
weighs > 150?
a. .1353
b. .5000
c. .0228
d. .7623
2. Averaging reduces:
a. Alpha
b. Mean
c. Variance
d. Standard Deviation
3. How do you get tighter confidence levels?
a. Change measurement technique to reduce random variable.
b. Reduce the level of confidence.
c. Increase the sample size to tight up the SEM.
d. All of the above.
Current Forum: exam 1 questions examples Read 43 times
Date: Wed Oct 8 2003 7:59 am
Author: Martin, Christine <clm6d5@studentmail.umsl.edu>
Subject: Re: User Questions
1. The EPA claims that a
certain car gets 25 miles per gallon or less when driven on the highway.
The manufacturer disagrees with this claim and wants to show that their
car gets better mileage. What is the alternative hypothesis?
a) Ho = 25
b) Ha < or = 25
c) Ho > 25
d) Ha < 25
e) Ha > 25
2. To show that x-bar (sample mean) is far enough away from the mean we will set up a rejection region. If the test statistic falls in the rejection region, we can:
a) Accept the null hypothesis
b) Reject the alternative
hypothesis
c) Accept the test statistic
d) Reject the null hypothesis
e) Reject the test statistic
3. If the result is to accept the null hypothesis, there is a chance that we are wrong. What type of error has occurred if we accepted the null hypothesis when we should have rejected it?
a) Rejection error
b) Type 2 error
c) Type A error
d) Type 1 error
e) Type B error
4. If the average miles per gallon for a Honda Civic is 35, and the standard deviation is 5, what is the probability of selecting a Honda Civic that gets more than 40 mpg?
a) .1587
b) .8413
c) 1.000
d) .3413
e) .5000
1) e, 2) d, 3) b, 4) a
Current Forum: exam 1 questions examples Read 40 times
Date: Wed Oct 8 2003 9:25 am
Author: Owen, Scott <shoyq9@studentmail.umsl.edu>
Subject: Re: User Questions from gkk7c5
1. Which one of the four situations is hypothesis testing not
commonly used?
a). Testing in decision-making situations.
b). Testing research hypotheses.
c). Testing validity of a claim.
d). Testing if-else statements.***
2. When formulating a null and alternative hypotheses, care must
be taken to be sure they are structured appropriately and that the
hypothesis-testing conclusion provides the information the user wants.
Which of the following would be the form of a two-tailed test?
a) Ho: p ©ø p0
Ha: p < p0
b) Ho: p ¡Â p0
Ha: p > p0
c) Ho: p = p0***
Ha: p ¡Á p0
d) Ho: p @ p0
Ha: p = p0
3) The Excel function, which computes the critical T value, is?
a) TINV***
b) TDIST
c) STDEV
d) TTEST
e) VAR
Current Forum: exam 1 questions examples Read 37 times
Date: Wed Oct 8 2003 10:47 am
Author: Ellis, Darnell <drey87@studentmail.umsl.edu>
Subject: Re: User Questions
1.) A graphical presentation of a frequency distribution, relative
frequency distribution, or present frequency distribution of quantitative
data constructed by placing the class intervals on the horizontal and the
frequencies on the vertical axis is
a.) Descriptive statistics
b.) linear regression
c.) scatter diagram
d.) histogram
correct answer d.
2.) In a test of HoM=100 against Ha M>100, the sample data gave the
test statistic , z=2.12. What is the approximate p-value of the test
a.) 17.0
b.) .017
c.) .107
d.) .0170
correct answer b.
3.) The equation used to get the mean of a population is
a.) xbar=Exi/n
b.) u=Exi/n
c.)osquare=E(x1-u)2/n
d.) s2=E(x1-xbar)2/n-1
correct answer a.
Current Forum: exam 1 questions examples Read 40 times
Date: Wed Oct 8 2003 11:19 am
Author: Smith, Harrison <hesq35@studentmail.umsl.edu>
Subject: Re: User Questions
1. When using a p-value when is the difference very highly signifigant?
a. Greater than 0.05
b. Greater than 0.01 but no more than 0.05
c. Less than 0.001 ***
d. Greater than 0.001 but no more than 0.01
e. none of the above
2. Which function is used to determine whether the difference between
two sample means is signifigantly different from zero?
a. F-test
b. t-test ***
c. z-test
d. regression
e. none of the above
3. What is the null hypothesis for a two-tailed F-test?
a. the variances are equal ***
b. the variances are not equal
c. the variance of the first is less than or equal to the second
d. the variance of the first is greater than the second
e. none of the above
Current Forum: exam 1 questions examples Read 39 times
Date: Wed Oct 8 2003 12:03 pm
Author: Kelley, Courtney <clk67d@studentmail.umsl.edu>
Subject: Re: User Questions
Given that x is normal with a mean of 47 and a stdev is 6.2, find the
probability that x<60.
A)0.33
B)0.08
C)0.9821****
D)0.7958
The standard error of a mean is:
A)standard deviation divided by the mean
B)standard deviation divided by the square root of the sample size.****
C)the mean divided by the standard deviation.
Degrees of freedom are needed when calculating?
A)z score
B)z distribution
C)t distribution****
Current Forum: exam 1 questions examples Read 45 times
Date: Wed Oct 8 2003 12:13 pm
Author: Smith, Harrison <hesq35@studentmail.umsl.edu>
Subject: Nevermind
got it figured out
Current Forum: exam 1 questions examples Read 39 times
Date: Wed Oct 8 2003 12:27 pm
Author: Owen, Scott <shoyq9@studentmail.umsl.edu>
Subject: Re: User Questions From Scott Owen
1. If the P value = .096215,
your T test is one tailed, and your alpha is 5%, what do you do?
a. P is less than alpha,
so reject H0.
b. P is greater than alpha,
so accept H0.
c. P is greater than alpha,
so you cannot reject H0. (Correct Answer)
d. P is less than alpha,
so you cannot accept H1.
2. When you want to derive
a paired statistic, you need:
a. A distinct value in one
column for every value in the other column. (Correct Answer)
b. Enough values so that
when combined, come out to an even amount.
c. A mean of “0”.
d. A difference of means
of “0”.
3. How do you derive the
confidence level of a statistic?
a. Standard Deviation /P
Value
b. T Value / Square root
of variance
c. Kurtosis always equals
confidence level
d. It is a subjective number
depending on needs (Correct Answer)
Current Forum: exam 1 questions examples Read 37 times
Date: Wed Oct 8 2003 12:35 pm
Author: McGovern, Sean <stmc47@studentmail.umsl.edu>
Subject: Re: User Questions
1. When doing a hypothesis test for two population means, the results
that are being sought are
a. p-values
b. critical t-values
c. point estimate
d. confidence interval
e. both a & b
2. Before doing the t-test: two sample assuming equal variances you should use what to check the variances.
a. the z-test:paired two sample for means
b. two sample assuming unequal variances
c. TINV Function
d. f-test two sample for variances
3. If the p-value is greater than 0.05 then the difference is
a. not significant
b. significant
c. highly significant
d. very highly significant
the answers are:
1. e
2. d
3. a
Current Forum: exam 1 questions examples Read 38 times
Date: Wed Oct 8 2003 1:19 pm
Author: McGee, Ryan <rcmfz9@studentmail.umsl.edu>
Subject: Re: User Questions
What is type one error?
aThe error of rejecting Ho when it is true
bthe error of accepting Ho when it is false
cA naturally occuring error
dThe error that is made first
eThe hypothesis concluded to be true if the null hypothesis is rejected
PLAR is what?
a please aptly reject
b P is less than alpha-reject
c the secret to life
d power level at rejection
e a type of interval estimation
What does the power of a test mean?
a how much the test can bench press
b the probably of correctly rejecting Ho when it is false
c it has a level of "power" to change your grade
d None of the above are true
e all of the above are true
answers A, B, B
Current Forum: exam 1 questions examples Read 32 times
Date: Wed Oct 8 2003 1:43 pm
Author: Almond, Janice <jsaz7c@studentmail.umsl.edu>
Subject: Re: User Questions
1. A two-tailed test is:
a. A testing situation in which the null hypothesis is refected for
the values of the point estimator only on one side
(tail) of the sampling distribution.
*b. A testing situation in which the null hypothesis is rejected for
values of the point estimator in either tail of the sampling distribution.
c. The test of the independence of two variables.
d. The analysis of two or more data samples.
2. A null hypothesis is:
*a. the hypothesis that is tentatively assumed to be true in hypothesis
testing.
b. An assumption made about the value of a population parameter.
c. A hypothesis that is proven 100% true.
d. A hypothesis that is proven 100% false.
3.Confidence level can best be described as...
a. Containing the value of the parameter.
b. The confidence placed on the ability of an interval estimate.
c. having a higher degree of confidence results in a larger margin
of error and larger width of the confidence interval.
*d. All of the above
Current Forum: exam 1 questions examples Read 34 times
Date: Wed Oct 8 2003 2:03 pm
Author: Owen, Scott <shoyq9@studentmail.umsl.edu>
Subject: Re: User Questions from Saraheliz82
How do you calculate the upper limit?
a. mean-confidence level
b. mean+confidence level
c. mean x confidence level
d. mean/confidence level
What does averaging do to the variance
a. increase variance
b. decrease variance
c. has no effect on the variance
d. none of the above
What does the T test do?
a. compares the means
b. calulates the cutoff value
c. both a and b
d. none of the above
Current Forum: exam 1 questions examples Read 37 times
Date: Wed Oct 8 2003 2:08 pm
Author: Koeb, Marcie <masrz4@studentmail.umsl.edu>
Subject: Re: User Questions
Q: A Z-Score is a
a. Raw score with a mean of zero;
b. Raw score with a mean of 50;
c. Standard score with a mean of zero;
d. Standard score with a mean of 50.
e. All of the above
Answer: c. standard score with a mean of zero
Q: A standard normal distribution has:
a. The mean equal to the variance
b. Mean equal 1 and variance equal 1
c. Mean equal 0 and variance equal 1
d. Mean equal 0 and standard deviation equal 0
e. None of these
Answer: c. mean equal 0 and variance equal 1
Q: In the standard normal distribution, what is the probability of finding a z value between -1.25 and -1.00?
a. 0.3944
b. 0.3414
c. 0.7357
d. 0.0531
e. none of the above
Answer: b. 0.3413
Current Forum: exam 1 questions examples Read 36 times
Date: Wed Oct 8 2003 2:10 pm
Author: Gagnon, Lawrence <ljgbp3@studentmail.umsl.edu>
Subject: Butch's Qs
#1The car dealer said that the jeep cheroke gwts 20 miles per gallon.
The book shows different claims that the car gets better mileage.
a)Ho=20
b)Ha c)Ha<20
d)Ha>20
#2 If using the p-value the test result is not significant when
a)less than or equal to .0001
b)If it's greater than .0001 or less than .1
c)If it's greater than .05
d)less than or equal to 5
#3 The z-value for .47 is
a).209
b).63
c).1808
d).003
correct answers #1=e #2=c #3=c
Current Forum: exam 1 questions examples Read 31 times
Date: Wed Oct 8 2003 2:12 pm
Author: Sabengsy, Viloath <vs476@studentmail.umsl.edu>
Subject: test questions
1. When testing the hypothesis
at an alpha level of significance:
Ho: µ ? 0.7.
Ha: µ > 0.7.
The null hypothesis will
be rejected if the test statistic Z is:
a. Z > Za.*
b. Z < Za.
c. Z < -Za.
d. Z < 0.
e. None of the above.
2. If the level of significance of hypothesis test is raised from 0.01 to 0.1, the probablility of a Type II error:
a. will increase from 0.01
to 0.05.
b. will not change.
c. will decrease.*
d. will increase.
e. None of the above.
3. In a test of Ho: M = 50 vs Ha: M > 50, the sample data gave the test statistic Z = 1.57. What is the approximate p-value of the test?
a. 0.0212
b. 0.0580
c. 0.0581
d. 0.0582*
e. 0.0583
• * denotes the answer
Vilo Sabengsy
MW 2-315
Current Forum: exam 1 questions examples Read 13 times
Date: Wed Oct 8 2003 2:39 pm
Author: Prouhet, Sarah <sjp882@studentmail.umsl.edu>
Subject: Re: User Questions
1. If P is less than alpha,
a. accept the null hypothesis
b. fail to reject the null hypothesis
c. reject the null hypothesis
d. fail to reject the alternative hypothesis
e. reject the alternative hypothesis
ANSWER: C
2. Which of the following is not needed for a t test?
a. sample means
b. degrees of freedom
c. standard deviation
d. sample size
e. both b and d
ANSWER: B
3. If researches claim that the mean body temperature of healthy adults
is not equal to 98.6 degrees F, and n=106, x bar = 98.2 degrees F, s =
0.62 degrees F, p-value = 0.0002, and the significance level is 0.05, which
of the following is true?
a. the test statistic is -4.64
b. the test is two-tailed
c. the null hypothesis is mean = 98.2
d. the alternative hypothesis is mean is less than 98.6
e. the conclusion is to reject Ho since the p-value is less than alpha
f. both b and e are correct
g. both c and b are correct
ANSWER: F
Current Forum: exam 1 questions examples Read 12 times
Date: Wed Oct 8 2003 3:11 pm
Author: Damalas, Alexander <ad7a3@studentmail.umsl.edu>
Subject: Re: User Questions
1. In testing variances before the T Test, an F score of 2.0 and F
critical of 2.3 means:
A. reject Ha
B. accept Ho, no need to do T test
C. F has no bearing on null hypothesis
D. treat variances as if they are equal
E. need more information
2. Consumer Reports is determining if the costs of printers is decreasing
over time. In 1998, the HP OfficeJet R40 cost on average 180 dollars. In
2001, they went to 25 retail outlets and recorded the new prices of the
same printer. What is the null hypothesis?
A. mean = 180
B. mean < 180
C. mean > 180
D. mean not equal to 180
E. need to know what the standard deviation is first
3. Suppose a 90 percent confidence interval for an estimate of a population
mean turns out to be (4500-9500). What does it mean to be 90 percent in
an inference that the true mean is in an interval?
A. In repeated sampling, the population parameter would be between
4500 and 9500 ninety percent of the time.
B. 90 percent of all the observations in the entire population fall
in this interval.
C. 90 percent of the observations in a sample will always fall in this
interval.
D. 90 percent of subsequent sample means would fall in this interval.
E. With enough repeated sampling, 90 percent of the intervals constructed
would include the population mean.
Correct answers: 1 D 2 A 3 E
Current Forum: exam 1 questions examples Read 7 times
Date: Wed Oct 8 2003 3:16 pm
Author: Taylor, Griffith <getkdb@studentmail.umsl.edu>
Subject: Re: User Questions
1. Type II Error occurs when:
(a) the null hypothesis is true and we reject it.
(b) the null hypothesis is true and we fail to reject it.
(c) the null hypothesis is false and we fail to reject it.
(d) the Ho is false and we reject it.
(e) the Ho aren't meant to be true.
Ans: C
2. Which of these these are used to compare variances?
(a) f-test
(b) t-test
(c) histogram
(d) z-test
(e) midterm
Ans: A
3. The average price of a VCR is $215. A consumer magazine is sampling
"street prices" to see if the average price has decreased. A sample of
VCR's will give an Xbar and a standard deviation. What is the Null hyptothesis,
Ho?
(a) ì < 215
(b) ì = 215
(c) ì not equal to 215
(d) ì > 215
Ans: B
Current Forum: exam 1 questions examples Read 7 times
Date: Wed Oct 8 2003 3:21 pm
Author: Gaines, Devon <dcgmr2@studentmail.umsl.edu>
Subject: Re: User Questions from gkk7c5
1. The value of alpha in a normal probability distribution with confidence
level 95% is which of the following?
a).10
b).05****
c).025
d).01
e).005
2. A product group has developed a new fuel injection system designed
to increase the miles per gallon rating. They are looking for evidence
that the new system increases the mean miles per gallon. They hypothesize
that the new system will provide a mean miles per gallon rating exceeding
24. Which is the appropriate alternative hypothesis?
a)Ha: X<24 ****
b)Ha: X>=24
C)Ha: X>24
d)Ha: X<=24
e)not enough information
3. In a sample for a one-tailed test with n=35, mean of 15.2, sample
mean of 14.3, and standard deviation of 5, which is the correct z-score?
a)1.07
b)-1.07****
c).75
d)1.03
e)none of the above
Current Forum: exam 1 questions examples Read 8 times
Date: Wed Oct 8 2003 6:55 pm
Author: Smith, Charles <cas676@studentmail.umsl.edu>
Subject: Re: User Questions
the error of rejecting the null hypothysis is:
a) a type I error *
b) a type II error
c) neither a) or b)
d) both a) or b)
For a test of Ho with the mean is 16 and Ha the mean os not 16, at alpha = 0.05, we calcuate a test statistic at 1.8. What conclusion can be made.
a) Reject the null
b) Cannot reject the null
c) We cannot tell with the given information*
d) we must conclude the null to be true at 0.05 alpha
If for a test of hypothyesis , your test statistic does not fall in the rejection region how can you manipulate the datta so that the test statistic will fall in the rejection region.
a) Decrease th confidence level
b) in crease alpha
c) decrease alpha
d) calculate the p-value
e) both a) and b) *
Discussion Board
Current Forum: example exam questions Read 47 times
Date: Wed Oct 8 2003 12:17 pm
Author: Banis, Robert <bud_banis@umsl.edu>
Subject: example questions
# How can you decrease the probability of a type II error?
1. decrease N
2. decrease alpha
3. improve the measurement
4. increase confidence level
***5. all of the above
# The scores on one of the most famous personnel tests were analyzed and yielded a Mu=90 and a standard deviation of 5. (sigma =5) Based on millions of test takers. What is the probability that a person picked at random will score between 90 and 75?
1. Z= .9544
2. Z= .7457
3. Z= .2072
4. Z= .5 (***)
5. very close to 0
6. almost 100%
# When using excel's two sample F-Test, what does it mean if your F-score is further out than your F Critical Value?
1. Accept Ho
2. Can not determine
***3. Reject Ho
4. F-value has no bearing on Ho
5. Hypothesis testing can only be done on normal distributions
# A population is known to have a left skewed distribution with a mean 400 and a standard deviation of 21. If samples of size N=49 are drawn at random from the population, the distribution of sample means will be
1. normally distributed with a standard deviation of 21.
2. left skewed with a standard deviation of 21.
3. left skewed with a mean of 400.
4. left skewed with s.d.=3
***5. normally distributed with a mean of 400.
6. right skewed, as a large enough sample makes it right.
Current Forum: example exam questions Read 14 times
Date: Wed Oct 8 2003 2:47 pm
Author: Wolfmeyer, Tricia <tmw985@studentmail.umsl.edu>
Subject: Q&A
What does PLAR mean
A.) P less than Alpha Reject
b.) This has no significance to Statistics
C.) P less than alpha Redo
D.) None of these are correct
Where is your analysis tool packet located?
A.) Under the funtion key
B.) Under Tools, and add ins
C.) In your Wizard chart
D.) Analysis tool packets are not used in this class
In Hypothesis testing how many ways can you be wrong?
A.) One
B.) two
C.) Three
D.) Never
Current Forum: example exam questions Read 11 times
Date: Wed Oct 8 2003 7:10 pm
Author: Mueller, Dennis <drmbp3@studentmail.umsl.edu>
Subject: possible exam questions
1.If you want to determine if a group has different means you should
use:
A. t-test
B.z-test
C. f-test
D. linear regression
E. paired difference
The answer is a.
2. To find the limits of the confidence level you should:
a. add/subtract the mean and the standard error
b. add/subtract the standard deviation and standard error
c. add/subtract the mean and the confidence level number given
d. add/subtract the mean and the standard deviation
e. cheat off of your neighbor
The answer is c.
3. If the probability is .40 what can you say about the hypothesis?
a. reject because of significant evidence
b. reject because of PLAR
c. accept
d. fail to reject but try again b/c it may have happened by chance
e. fail to reject and not try again because it did not happen by chance.
The correct answer is e.
Current Forum: example exam questions Read 14 times
Date: Wed Oct 8 2003 7:18 pm
Author: Hruby, Robert <rsh189@studentmail.umsl.edu>
Subject: example exam questions mutliple choice
1. The effect one variable being modified by the other variable is
referred to as?
A. correlation
B. interaction
C. interval estimation
D. extraction
E. type I error
answer B
2. Which descriptive statistic gives the value that occurs most often
within a sample?
A. mean
B. median
C. mode
D. standard deviation
E. kurtosis
answer C
3. The histogram graphs the _______ from the sample values given.
A. variance
B. frequency
C. mean
D. standard deviation
E. sum of squares
answer B
Current Forum: example exam questions Read 12 times
Date: Wed Oct 8 2003 7:18 pm
Author: Henderson, James <jrhrv4@studentmail.umsl.edu>
Subject: test ?s
1. Which or all of these examples uses a two tail test?
A. Chinese smokers. Are they smoking more or less in 2003.
B. Females and males differ in height.
C. Averade price of movies is decreasing from $12 t0 $20.
D. a and b
E. a and c
2. A test statistic:
A. depends on th selected confidence level
B. Is hypothesized in the null hypothesis
C. Is what is actually observed when the situation in measured
D. Is the average on the variance of two samples
E. Is the average of the means of two samples
3. Which of these is needed to calculate p-value in the T test
A. Hypothesised mean
B. beta
C. df
D. alpha
E. two tails
Current Forum: example exam questions Read 5 times
Date: Wed Oct 8 2003 8:01 pm
Author: Finley, Melissa <mcfvz9@studentmail.umsl.edu>
Subject: questions
1. What would you "not do" to make a test more likely the null hypothesis
would be rejected when it is really false?
A. increase the alpha level
B. increase sample size
**C. increase the beta level
D. have people enter the data at home
2. A type 1 error is:
A. accepting Ho when it is false
**B. rejecting Ho when it is true
C. when the value of the test statistic is not in the
rejection region.
D. do not reject H0, and not accept HO
3. Next summers rain yield in Missouri is a normal distribution with
a mean of 14 inches ans a standard deviation of 3. The farmers will be
profitable if the yields are at least 18 inches of rain in the summer.
Whats the probability the farmers will loose crops next summer?
A. 32%
B. 6%
**C. 91%
D. Not enough of information
Current Forum: example exam questions Read 5 times
Date: Wed Oct 8 2003 8:08 pm
Author: Lehmen, Elizabeth <eml4f4@studentmail.umsl.edu>
Subject: questions for test
1. If your reject Ho when it is true you have...
**a. a Type I Error
b. a Type II Error
C. a Type III Error
d. an Error in the null hypothesis.
e. a big problem
2. Which is NOT part of the Centeral Limit Theorem?
a. sample mean is true mean
**b. T critical is greater than T observed
c. normal shaped curve
d. Standard error is standard deviation divided by the squareroot of
the number
e. a curve skewed to the right
3. When do you treat variances as equal?
a. when T critical is greater than T observed
b. when means are equal
**c. when F score is closer to one than is F critical
d. when alpha is .05 or greater
e. when T is closer to one than is T critical
Current Forum: example exam questions Read 6 times
Date: Wed Oct 8 2003 8:10 pm
Author: Runde, Kevin <klra86@studentmail.umsl.edu>
Subject: sample exam questions
1. In using Excel for statistical analysis, which of the following
functions is
used in calculating the P-Value of a test hypothesis?
A. TTest()
B. STDEVP()
C. TINV()
D. TDIST()
E. SQRT()
Correct Answer: D
2. In comparing two means for the analysis of variance, which of the
following
is false?
A. null hypothises : (mu)1 not equal to (mu)2
B. Compares difference between sample means vs. a pooled
estimate of standard deviation.
C. Use Z test or t test depending on whether s is known or
sample size > 25.
D. all of the above are true
Correct answer: A -the null hypothesis must have equal variances
3. The Central Limit Theorem states that:
A. mean sample means-->true mean
B. shape-->normal
C. stderror of the means=stdev/sqrt(n)
D. none of the above
E. all of the above
Correct answer: E
4. A failure to reject H0:
A. occurs when P is less than alpha
B. means that the null hypothesis must be true
C. means the researcher failed to provide evidence sufficient to cast
serious
doubt on the truth of H0
D. Both B and C
E. None of the above
Correct answer: C
Current Forum: example exam questions Read 5 times
Date: Wed Oct 8 2003 8:12 pm
Author: Sydnor, Teresa <tlsz8d@studentmail.umsl.edu>
Subject: Re: example questions
QUESTION #1
The acronym PLAR stands for:
A. Probability Large Always Reject.
B. Probability Less than Alpha Reject
C. Please Let my Answer be Right
D. Pay Little Attention to the Reading
E. Pick the Last Answer Rarely
Answer B
QUESTION #2
The test the Null Hypothesis you set the assumption:
A. =
B. >
C. <
D. Not Equal
E. You don't test the null hypothesis, you test the alternate hypothesis.
Answer A
QUESTION #3
Descriptive Statistics consists of the following:
A. Mean
B. Standard Deviation
C. Standard Error
D. All of the above
E. None of the Above
Answer D
Current Forum: example exam questions Read 7 times
Date: Wed Oct 8 2003 8:19 pm
Author: Felton, Mark <mtf188@studentmail.umsl.edu>
Subject: questions
1. What is interaction
A. The effect of one variable is modified by another
B. Two people talking together
C. The idea that the z and t scores are equal
D. Type I risk
E. Type II risk
2. Averaging eliminates what
A. The need to compute pvalue
B. The sample mean
C. Beta
D. Variance
E. The likelihood of two means being the same
3. What is type II risk
A. Reject the hypothesis even though it's not false
B. PLAR
C. Failed to reject when false
D. The curve is not normal
E. The possibility of catching a cold
Current Forum: example exam questions Read 5 times
Date: Wed Oct 8 2003 8:19 pm
Author: Pudik, Molly <mcpgf4@studentmail.umsl.edu>
Subject: exam questions
1. General statistical practice is to assume that for most applications
the sampling distribution of x bar can be approximated by a normal probability
distribution whenever the sample size is 30 or more. This describes the:
A: standard error of the mean
B: central limit theorem
C: degrees of freedom
D: normal probability distribution
E: cluster sampling
Answer: B
2. If probability is less than alpha you would:
A: reject the null hypothesis
B: accept the null hypothesis
C: fail to reject the null hypothesis
D: retry until probability is equal to alpha
E: none of the above
Answer: A
3. The value added to and subtracted from a point estimate in order
to develop an interval estimate of a population parameter is :
A: interval estimate
B: sampling error
C: precision statement
D: confidence coefficient
E: margin of error
Answer: E
Current Forum: example exam questions Read 5 times
Date: Wed Oct 8 2003 8:31 pm
Author: Felton, Mark <mtf188@studentmail.umsl.edu>
Subject: Re: questions
Answers
1. A
2. D
3. C
Current Forum: example exam questions Read 4 times
Date: Wed Oct 8 2003 8:36 pm
Author: Miller, Samantha <samrzf@studentmail.umsl.edu>
Subject: Re: questions
1. What is the confidence level expressed as?
A. alpha + beta
B. beta - alpha
C. a percentage
D. an equation
2. The sampling distribution of both the z and t statistic looks like
what?
A. a mound shaped symmetric with the mean of zero
B. a double mound graphed on the same axis
C. a mound shaped symmetric with the mean of any number greater than
one
D. two seperate mounds graphed each on their own axis
3. In a t statistic equation (n-1) is refered to as?
A. the null hypothesis
B. the alternative hypothesis
C. degrees of freedom
D. the mean
Current Forum: example exam questions Read 4 times
Date: Wed Oct 8 2003 8:41 pm
Author: Brewer, Constance <cmb021@studentmail.umsl.edu>
Subject: Re: Q&A
1. What happens when you increase the confidence level?
a. you should reject the Ho
b. increase alpha
**c. decrease alpha
d. your results are more accurate
c. you should accept the Ho
2. What is the variance if the standard deviation is 1.97?
**a. 3.87
b. 4
c. 1.40
d. 0.015
e. 1
3. The cut off point represents what value?
a. Pvalue
b. Tobserved
c. z value
**d. the critical T value
e. alpha
4. If there is a change in the level of one variable what can this cause?
**a. there change in the level of one variable can affect the change
in another variable.
b. the sample can no longer be used
c. you must accept the Ho
d. alpha becomes smaller
e. Pvalue will be smaller than alpha, thus we must reject the Ho
5. What does the confidence level represent?
a. the area on the graph when you must reject the Ho
b. the area on the graph when you must accept the Ha
c. alpha
d. the degrees of freedom
**e. the area on the graph between the two tails (alpha) where the
mean is
Current Forum: example exam questions Read 6 times
Date: Wed Oct 8 2003 8:52 pm
Author: Jones, Keith <ksj423@studentmail.umsl.edu>
Subject: Sample Test Questions
The +/- value added to and subtracted from a point estimate in order
to develop an interval estimate of a population parameter is known as?
A) interval estimate
B) margin of error
C) confidence level
D) degrees of freedom
E) sampling error
Answer= B
A value that is used to determine whether a null hypothesis can be rejected
is known as?
A) critical value
B) p-value
C) test statistic
D) interval estimate
E) point estimate
Answer= C
When comparing two variances what type of test should be used?
A) hypothesis test
B) z test
C) t test
D) f test
E) two-tailed test
Answer= D
Current Forum: example exam questions Read 3 times
Date: Wed Oct 8 2003 9:01 pm
Author: Stone, Theresa <tis7t3@studentmail.umsl.edu>
Subject: Re: example questions
For Alpha = .05 for which of the following p-values would th e null
hypothesis be rejected?
**A. 0.04
B. 0.07
C.2.97
D.0.051
One-tail or two-tail test?
A. Does the redesigned Thunderbird go faster? (*1-Tail)
B. Kids under 21. Are they drinking more or less than in 1872? (*2-Tail)
C. The average price of CD players has decreased from $90 in 1995 (*1-Tail)
What does the hypothesis look like in a two tail test?
A. Ha:u=uo
*B. Ha:u does not = uo
c. Ha:u
d. Ha:u>uo
Current Forum: example exam questions Read 11 times
Date: Wed Oct 8 2003 9:17 pm
Author: Groh, Scott <stgqk7@studentmail.umsl.edu>
Subject: Re: example questions
1. What does averaging the means do?
A. Makes them all approximately the same.
***B. Averaging eliminates variance.
C. Makes the means all different.
D. The means are greater than the average.
E. The means are less than the average.
Current Forum: example exam questions Read 8 times
Date: Wed Oct 8 2003 9:27 pm
Author: Groh, Scott <stgqk7@studentmail.umsl.edu>
Subject: Re: example questions
2. What is not true of the Central Limit Theorem.
A. The shape will be normal.
B. The mean of x bar --> mean of x.
C. The standard deviation of x bar --> standard deviation of x divided
by square root of n.
D. The sample size needs to be sufficient for the Central Limit Theorem
to be true.
***E. The mean of x --> mean of x bar.
3. If P value is less than alpha we conclude:
***A. Reject the assumptions.
B. Accept the assumptions.
C. The confidence level is high so we fail to reject.
D. The assumptions are insufficient.
E. The probability is so low that we would observe this again that
we reject.
Current Forum: example exam questions Read 3 times
Date: Wed Oct 8 2003 10:41 pm
Author: Moormann, Bryan <bjm67b@studentmail.umsl.edu>
Subject: sample questions
1. What is the standard error of a sample if n=64 and the variance
is 3600?
a. 56.25
b. 450
c. 0.9375
d. 7.5
e. 60
2. If one is conducting a two-tailed F-test and population 1 and 2 have variances of 10 and 15, respectively, what does the F score mean if F critical is 0.3?
a. The sample means are equal
b. The populations are the same
c. Treat the variances as if they are equal for the t-test
d. Reject Ho, treat the variances as if they are equal
e. accept Ho, no need to do t-test
3. Which one of these is not needed to perform a t-test procedure?
a. Number of tails
b. Standard deviation
c. Alpha
d. Sample mean
e. All of the above are needed
answers: 1. d 2. c 3. e
Current Forum: example exam questions Read 2 times
Date: Wed Oct 8 2003 10:54 pm
Author: Toll, Daniel <datvw9@studentmail.umsl.edu>
Subject: Re: example questions
1) Interaction refers to
A. the difference between alpha and beta.
**B. the change in the level of one variable caused by the change in
the level of another.
C. the difference between the confidence level and alpha.
D. the relationship between a t-score and a z-score.
E. none of the above
2) Degrees of freedom are
A. Always 100%
B. Always 0%
C. the same as alpha.
*D. the number in the sample, minus 1.
E. None of the above.
3) A graph of a standard distribution will have what shape?
A. A circle
*B. A bell-shaped curve
C. A linear shape
D. 3-D cubic shape
E. A pie shaped graph
Current Forum: example exam questions Read 3 times
Date: Wed Oct 8 2003 10:58 pm
Author: Krahl, Antonio <ark5h6@studentmail.umsl.edu>
Subject: exam questions
1.) What are we testing, when using a F test?
A if groups sampled have different means
B if the difference between sample means is zero
C if the variances of samples are equal
D if we can use the Z- or the T-table
E if P is greater than Alpha
Answer C
2.) The null hypothesis in a F test is:
A Ho: variance1/variance2=1
B Ho: variance1-variance2=0
C Ho: variance1=variance2
D all of the above are possible Ho´s
E non of the above
Answer D
3.) An observed F score of 1.7 and F critical=1.5 means:
A treat variances as if they are equal for t test
B treat variances as if thy are unequal for t test
C samples are from the same population
D sample size was not big enough
E we have to repeat the calculation
Answer B
Current Forum: example exam questions Read 5 times
Date: Wed Oct 8 2003 11:15 pm
Author: Gyuriseck, Timothy <tag103@studentmail.umsl.edu>
Subject: Questions
1. Which of the following cannot be concluded from the Central Limit
Theorem:
A. The Shape of the curve will be symmetrical
B. The mean of all possible sample means will be equal to the population
mean
C. It will be a normal bell shaped curve
D. If the Pvalue is less than alpha, then reject the Ho
E. The standard deviation of Xbar is helpful in determining how far
the sample mean may be from the population mean
Answer: D
2. In Excel, which of the following is not needed for a t-Test: Two
Sample Assuming Equal Variances:
A. Variable 1 Range
B. Alpha
C. Variable 2 Range
D. Hypothesized Mean Difference
E. Degrees of Freedom
Answer: E
3. Using a 95% confidence level, which of the following is true given
a Pvalue of .04:
A. Since p
B. Reject the Ho, but since p
C. Reject the Ho, but since p
D. Not enough information to conclude anything
E. Reject the Ha, and fail to reject the Ho
Answer: B
Current Forum: example exam questions Read 2 times
Date: Wed Oct 8 2003 11:19 pm
Author: Gyuriseck, Timothy <tag103@studentmail.umsl.edu>
Subject: Resubmitting: Questions
1. Which of the following cannot be concluded from the Central Limit
Theorem:
A. The Shape of the curve will be symmetrical
B. The mean of all possible sample means will be equal to the population
mean
C. It will be a normal bell shaped curve
D. If the Pvalue is less than alpha, then reject the Ho
E. The standard deviation of Xbar is helpful in determining how far
the sample mean may be from the population mean
Answer: D
2. In Excel, which of the following is not needed for a t-Test: Two
Sample Assuming Equal Variances:
A. Variable 1 Range
B. Alpha
C. Variable 2 Range
D. Hypothesized Mean Difference
E. Degrees of Freedom
Answer: E
3. Using a 95% confidence level, which of the following is true given
a Pvalue of .04:
A. Since the Pvalue is less than alpha, you must recalculate the answer
using a 99% confidence level
B. Reject the Ho, but since the Pvalue is less than alpha you might
have a Type I Error
C. Reject the Ho, but since the Pvalue is less than alpha you might
have a Type II Error
D. Not enough information to conclude anything
E. Reject the Ha, and fail to reject the Ho
Answer: B
Current Forum: example exam questions Read 1 time
Date: Wed Oct 8 2003 11:38 pm
Author: Chong, Andre <atc244@studentmail.umsl.edu>
Subject: exam questions
1) As the sample size becomes larger, the sampling distribution
of the sample meanapproaches a
a. Binomial distribution
b. Normal distribution
c. Hypergeometric distribution
d. chi-square distribution
Answer: b
2) In hypothesis testing, the hypothesis which is tentatively
assumed to be true is called the
a. correct hypothesis
b. level of significance
c. alternative hypothesis
d. null hypothesis
Answer: d
3) The t value for a 95% confidence interval estimation with 28
degrees of freedom is
a. 2.467
b. 2.052
c. 2.048
d. 2.473
Answer: c
Current Forum: example exam questions Read 1 time
Date: Thu Oct 9 2003 1:36 am
Author: Gitonga, Ann <ang21b@studentmail.umsl.edu>
Subject: Re: example questions
1. Type I error occures when: A. we reject Ho when it is true and also
reject Ha when true. B. we accept that Ho is false but find Ha is true
also. C. we reject Ho when true , but if Ha is true rejecting Ho is correct.
D. we reject Ha when true and accept Ho because you cannot accept both.
E. none of the above.
Answer: C
2. Which one of the following is false about test statistic?
A. The values of the test statistic are used in only on the one tail.
B. Critical value is defines the rejection region in the test statistic.
C. Test statistic is used to draw conclusion in a hypothesis.
D. The level of sigificance is used in a test statistic.
E. All are true.
Answer: A
3. Margin of error is defined as the value added to and subtracted from
a _____________ in order to develop an interval estimate of a population
parameter.
A. sampling error
B. point estimate
C. standard error
D. degrees of feedom
E. confidence level
Answer B
1. If P is less than alpha,
a. accept the null hypothesis
b. fail to reject the null
hypothesis
c. reject the null hypothesis
d. fail to reject the alternative
hypothesis
e. reject the alternative
hypothesis
ANSWER: C
2. Which of the following is not needed for a t test?
a. sample means
b. degrees of freedom
c. standard deviation
d. sample size
e. both b and d
ANSWER: B
3. If researches claim that the mean body temperature of healthy
adults is not
equal to 98.6 degrees F, and n=106, x bar = 98.2 degrees F, s = 0.62
degrees F,
p-value = 0.0002, and the significance level is 0.05, which of the
following is
true?
a. the test statistic is
-4.64
b. the test is two-tailed
c. the null hypothesis is
mean = 98.2
d. the alternative hypothesis
is mean is less than 98.6
e. the conclusion is to
reject Ho since the p-value is less than alpha
f. both b and e are correct
g. both c and b are correct
ANSWER: F
Sarah Prouhet
Test Questions
1. The EPA claims that a certain car gets 25 miles per gallon or less when driven on the highway. The manufacturer disagrees with this claim and wants to show that their car gets better mileage. What is the alternative hypothesis?
a) Ho: ì = 25
b) Ha: ì ? 25
c) Ho: ì > 25
d) Ha: ì < 25
e) Ha: ì > 25
2. To show that x-bar (sample mean) is far enough away from the mean
(ì o) we will set up a rejection region. If the test statistic
falls in the rejection region, we can:
a) Accept the null hypothesis
b) Reject the alternative hypothesis
c) Accept the test statistic
d) Reject the null hypothesis
e) Reject the test statistic
3. If the result is to accept the null hypothesis, there is a chance that we are wrong. What type of error has occurred if we accepted the null hypothesis when we should have rejected it?
a) Rejection error
b) Type 2 error
c) Type A error
d) Type 1 error
e) Type B error
4. If the average miles per gallon for a Honda Civic is 35 and the standard deviation is 5, what is the probability of selecting a Honda Civic that gets >40 mpg?
a) .1587
b) .8413
c) 1.000
d) .3413
e) .5000
Chrissie Martin
Answers: 1) e, 2) d, 3) b, 4) a
Nick Young
2:00-3:15
student #= 001105422
1) A population has a mean of 1000 and a standard deviation of 240.
If a
random sample of 64 with a mean of 928 gives you a Z score of
2.4, what is
the standard deviation of the sample?
A) 3
B) 30***
C) 240
D) Not enough information
E) None of the above
2) In Excel, what function do you use to get a Pvalue from a Tvalue?
A) TINV
B) T-test: Two Sample Assuming Equal Variances
C) T-test: Two Sample Assuming Unequal Variances
D) TDIST***
E) None of the above
3) What is the significance of using a paired T-test compared to using
a
T-test of differences?
A) It reduces the variance associated between the two variables***
B) They are the same kind of test
C) A paired T-test includes more factors contributed to variance
D) There is no significance
E) None of the above
Question 1: On a scatter graph, if the points are right on top of the
trendline, what is happening?
A. The points conclude to say that there is a huge difference
between the two samples.$$$$
B. The points conlcude to say that there is minimal difference
between the two samples.
C. It isn't a large enough sample to conclude anything
D. Both A and C
Question 2: With this information, what is the probability of
finding a point ouside the area?
Eddie Vorreiter
2:00 1085837
1. The random variable x is known to be uniformly distributed
between 1 and
1.5. Find P(x=1.25)
2. An airline quotes a flight time of 2 hours, 5 minutes for its
flight from
St. Louis to Atlanta. Suppose we believe that actual flight times
are
uniformly distributed between 2 hours and 2 hours, 20 minutes.
What is the
probability that the flight will be more than 10 minutes late?
3. The random variable x is known to be uniformly distributed
between 10 and
20. Find E(x).
Question 1: On a scatter graph, if the points are right on top of the
trendline, what is happening?
A. The points conclude to say that there is a huge difference
between the two samples.
B. The points conlcude to say that there is minimal difference
between the two samples.$$
C. It isn't a large enough sample to conclude anything
D. Both A and C
Question 2: With this information, what is the probability of
finding a point ouside the area on a one tail test?
Variable 1
Variable 2
Mean
51.85
49.535
Variance
121.58337
118.7078
Observation
100
100
Pooled Variance
120.1457
Hypothesized mean difference
0
df
99
TStat
1.494065
P(T<=t)one tail
.0068375
t critical one tail
1.285841
P(T<=t)two tail
.136751
t critical two tail
1.652586
A. less than 1%
B. 6.8%
C. 12.85%
D. 52%
E. so close to one hundred, it almost happens every time.
Why is it important to know if the variance is equal or not when dealing
with the t-test??
Keith Hinkebein
Kevin Runde
s#:1082102
BA3300 sec E02
1. In using Excel for statistical analysis, which of the following functions
is
used in calculating the P-Value of a test hypothesis?
A. TTest()
B. STDEVP()
C. TINV()
D. TDIST()
E. SQRT()
Correct Answer: D
2. In comparing two means for the analysis of variance, which of the
following
is false?
A. null hypothises : (mu)1 not equal to (mu)2
B. Compares difference between sample means vs. a pooled
estimate of standard deviation.
C. Use Z test or t test depending on whether s is known or
sample size > 25.
D. all of the above are true
Correct answer: A -the null hypothesis must have equal variances
3. The Central Limit Theorem states that:
A. mean sample means-->true mean
B. shape-->normal
C. stderror of the means=stdev/sqrt(n)
D. none of the above
E. all of the above
Correct answer: E
4. A failure to reject H0:
A. occurs when P is less than alpha
B. means that the null hypothesis must be true
C. means the researcher failed to provide evidence sufficient
to cast serious
doubt on the truth of H0
D. Both B and C
E. None of the above
Correct answer: C
5. How many colleges in the United States offer Logistics and Operations
Management as a four year degree program?
A. 10
B.143
C. 18
D. 1
E. 74
Correct Answer: D - According to professor Campbell UMSL is the only
school
that offers LOM as a major (most schools call the program management
science or
something to that effect)
1. If alpha is .05, what p value would cause us to reject the null
hypothesis?
A. .10
B. .90
C. .65
D. .06
E. .001****
2. If researchers were to calculate the difference in sales volume
for the
two flea markets in Bourbon, MO for each of many random days and then
analyze the differences, what type of experiment is being conducted?
A. Paired difference
B. Z test
C. F test
D. Paired differnce****
E. Linear regression.
3. The confidence level is determined by:
A. Standard deviation divided
by Tcrit.
B. Tinverse multiplied by Standard
Error.***
C. Variance added to mean.
D. P value multiplied by alpha.
E. Mean divided by Standard Error.
1. What specifically does the f-test tell us?
a. Whether the samples are equal
b. Whether the sample means are equal
c. How large the difference between population means are
d. **Wheter the sample variences are equal
e. What the size of the sample means are with respect
to the t distribution
2. What does increasing the sample size do to our hypothesis testing?
a. It makes our p-values smaller
b. **It makes our p-values larger
c. It makes our alpha larger
d. It makes our beta larger
e. It makes our alpha smaller
3. When the null hypothesis is rejected, but is true that is called
a(n)
a. **Type I error
b. Bad guess
c. Aerithmatic error
d. Type II error
e. Sampling error
4. The degrees of freedom are simply
a. How often you can be wrong in hypothesis testing
b. How wrong you can be in hypothesis testing
c. How many minutes past curfew your parents "really"
let you sty out
d. The range in which the average of the means falls
e. The sample size less one
1) What is a type II error?
a)Accept Ho, but Ha is true
b)Ho and Ha are true
c)determining the wrong p-value
d)determining the wrong t-statistic
e)determined the correct critical value
2)What is the critical value?
a)The range of values that will lead to the rejection of the null
hypothesis
b)The max allowable probability of making a Type I error
c)A value that is compared w/the test statistic to determine whether
Ho
should be rejected
d)The probability that Ho is true
e)The probablity of correctly rejecting Ho when it is false
3) Which of the following statements is correct regarding the
standard
normal distribution?
a. It is also the z distribution
b. Alpha is always .05
c. Mean is 0 and the standard deviation is 1
d. It is also called hypothesis testing
1. Which one of the four situations is hypothesis testing not
commonly used?
a). Testing in decision-making situations.
b). Testing research hypotheses.
c). Testing validity of a claim.
d). Testing if-else statements.***
2. When formulating a null and alternative hypotheses, care must
be taken to be sure they are structured appropriately and that the
hypothesis-testing conclusion provides the information the user wants.
Which of the following would be the form of a two-tailed test?
a) Ho: p ©ø p0
Ha: p < p0
b) Ho: p ¡Â p0
Ha: p > p0
c) Ho: p = p0***
Ha: p ¡Á p0
d) Ho: p @ p0
Ha: p = p0
3) The Excel function, which computes the critical T value, is?
a) TINV***
b) TDIST
c) STDEV
d) TTEST
e) VAR
1. The normail distribution is a
a. discrete distribution
b. continuous distribution
c. positively skewed distribution
d. none of the above
2. Which of the following are correct statements about a normal
distribution?
a. It is a symmetric distribution
b. It is bell-shaped
c. It is asymptotic
d. All of the above
My name is Mary Floyd
Question 1
The acronym PLAR stands for:
A. Probability Large Always Reject
B. Probability Less than Alpha Reject
C. Please Let my Answer Be Right
D. Pay Little Attention to the Reading
E. Pick the Last Answer Rarely
Answer B
Question #2
To test the Null Hypothesis you set the assumption:
A. =
B. >
C. <
D. Not Equal
E. Don't test the null hypothesis you test the alternative hypothesis
Answer A.
Question #3
Descriptive Statistics consists of the following:
A. Mean
B. Standard Deviation
C. Standard Error
D. All of the Above
E. None of the Above
Answer D