Approximate
timing
| Monday
MLK Day Holiday doesn't affect schedule |
Overview, review of Z and t distributions, hypothesis testing. The Central Limit Theorem. One sample t-test.
Review of Netscape Navigator/MS Internet Explorer, Windows Explorer and EXCEL Editing, converting and cleaning up real data-Descriptive Statistics, Graphing, t-tests. Comparing two sample means.Normsdist function:
Be the "Martha Stewart" of Statistics-- make your own Z score Table. The "Martha Stewart" table of critical t's (and a more complex version of t-tail probabilities)
| Exercise 1: Sampling and the central limit theorem.
Due before the end of the day Thursday, February 3 using the random sampling procedure, collect 20 samples of size n=25 from the airplane empty seat data. derive means, standard deviations and 95% confidence intervals for estimates of the population mean for each of the 20 samples. compare histograms of the original distribution and the distribution of sample means. Turn in the resulting spreadsheet printed to be 1 page (legible) with your name, section and student number printed at the top of the sheet. You can accomplish this by printing a selected range that leaves out some of the original data. Also submit a file via the Mygateway dropbox. be sure to click send to submit. How many of your samples had intervals including the true mean? How many gave an erroneous estimate? What is the expected frequency of errors in estimating the population mean when you use a 95% confidence interval? Was your observed result close to that expectation? State the three characteristics we expect to see in the distribution of sample means from the Central Limit Theorem. Are your results reasonably consistent with those expectations? |
Hypothesis testing and sample means h0test.pdf
Caution in the interpretation of hypothesis test!Comparison of sample variances through F tests, comparison of sample means, controlled experiments, Ch 9
| Exercise 2:
Click here for Detailed Description with questions to guide you in interpretation Paired ttest on gender and grades Due before the end of the day Tuesday March 1. Required (or no grade): 1)Print your name and student number (STUDENT NUMBER--up to 50 points will be taken off for not using the student number) at the top of the sheet. use the last 4 digits of your student number in the data in place of A,B,C,D. 2)Print interpretations in text boxes by the procedures they refer to. See the completed example we did in class on the salaries data. 3)Turn in the spreadsheet printed to be 1 page-legible. You can accomplish this by printing a selected range that leaves out some of the original data. 4)Also submit a file via the Mygateway dropbox.Title it Exercise 2. Be sure to click "add" and then "send" to submit. |
Variance and Standard Deviation:
Ch 6 Describing data measures of central tendency: dispersity Areas under the normal curve-- the Z score table . Applications to normallized scores--the IQ Score examplesCentral Limit Theorem
Sampling Statistics and confidence limits on estimates of parameters. Ch 7 Sampling from Airplane empty seats data CXA07_01.PRNvideo sample.avi Results show Central Limit Theorem on distribution of sample means.
Joint probabilities and probabilities of multiple errors in the sampling experiment. Normal approximation to binomial distribution.
Hypothesis testing and sample means
Example one-sample t-test: Is hospital length of stay < 5 days?Beta error & sample size losbeta.xls
T-test two sample means:
gender and height data from classheight data 2 sample t test completed
paired Sample T test:
Example on salary related to gender: Power of controlling other variables through Paired comparisons Male & Female Salaries are they significantly different? Results with interpretation: sexsalt.xlsApplication of confidence intervals when data consists of population proportions Drug Use Survey
Exam 1--There will be the paper exam with mostly MC questions.Thursday will be the hands on exam where you demonstrate skill with procedures as well as interpretation of the EXCEL output. Exam 1 questions by discussion board due by Tuesday Mar. 1 The hands-on exam will have at least a histogram, descriptive
statistics, various t-tests and interpretations.
|
Ch 13 Analysis of Variance
Concepts of ANOVA , "explaining variance" Where does it come from and how can you mathematically separate out the sources of variation?EXCEL model showing partition of Variance by averaging out different effects. Be sure to set Tools >Macro >security at "medium" and enable the macros so the drop down list works.
| Exercise 3 Store sale prices due Thursday, March 31 |
Ch 14 & 15 Regression
-- Simple Correlation And Linear Regression (pdf regression overview)See the Varsorc modelabout detecting effects in the presence of other factors
Regression least squares fit equations and EXCEL equivalent functions
Golf balls and clubs data cxa15_06.prn
Video with sound 1-Factor ANOVA2-Factor ANOVA with Replication
Screen captures of golf club example if you want to see how means could be adjusted to arithmetically to do what is done in ANOVA, canceling the treatment effects. golfadj1.jpg
and golfadjf.jpg , showing formulas 2wayanov.xls
completed comparisons showing "manual" calculations golf9.xls
More Discussion
Ch 14 & 15 Regression
Is crime related to level of gambling activity? Quadratic models-- Electricity Usage and size of house, kwhuse.xls , results kwhuse9.xls
Learning Curves, assembly.dat results 9 am how does this relate to learning curve theory?
data for paste special/ transpose. Interaction example from book--the clock auction.
Examples of CHISquared studies:Note you can save just the analysis in a small file separate from the data by copy/paste into a new sheet. Just be sure to paste in the same cells as there are absolute references that might otherwise be messed up.Examples for highschool program: just percents --metrostatus and dangerous behaviors --Increase in Marijuana Use with Age --Marijuana Use and Grades --Marijuana Use and Suicide news item highschool girls using steroids YRBSS2001 data with smoking vs. Sex
Grade in school vs. age distributions-2003 Sexual experience and carrot consumption: carrotx2.xls |
| EXC grades available until last drop day |
(YRBSS data Weight Multiple Regression
Exercise 4-Due Thursday April 21)-we'll walk through the actual exercise together in class --each person with their own individualized data) to complete a larger dataset Multiple regression with about 14,000 records, studying the age, gender, height effects on weight of highschool students from The Youth Risky Behavior Surveillance System (YRBS)
Click here for detail on the assignment. See the Multiple Regression Video for explicit details
See the screen captures on parsing the
2003 data into EXCEL.
Chi-squared analysis for independence
Crosstabulation of variables can most simply be done by pivot tables in EXCEL. See the videos and an example sheet on the YRBS2001 data.We will use pivot tables in EXCEL to generate the data we need from YRBS2003 for chi2 analysisWe will walk through this together in class.
Exercise 5-due before Thursday April 28, the last class)--get it in early, none accepted after April 28 (at the end of the semester, due dates are firm to allow for timely grading )
a printable version of the exercise in WORD
More detail on pivotTables in EXCEL, usepivot.doc
| Crosstabulation can also be done in ACCESS. See the videos on importing
the YRBS99 into ACCESS that are on the BA103 site--the procedure
is similar to the EXCEL Wizard Management
of large files using FTP or Winzip
Crosstabulating variables in ACCESS to preprocess for statistical analysis. Chi Square can be done on ACCESS crosstabulated data from the YRBSS. Crosstab Query video |
Ch 12. Categorical Analysis Chi Square tests of independence drinking and smoking. Spreadsheet formulas: smkdrkfo.jpg There are, of course, several ways to approach the calculation of the table of expected values. Another approach used in class F02 is shown in smkdrkf2.jpg
Copying text out of a PDF: pdftxt.avi
and pasting into EXCEL pastechi.avi
Formulas are designed to accomodate new problems by inserting or deleting
rows or columns expchi.avi Then
all you have to do is paste the observed values into the first table, and
the whole sheet will recalculate to give the solution.
Father's and son's career paths
This is a problem taken from the old text book, p.965,
problem 16.38. Pasting new data from the strangely arranged file
that came with the book into a modified sheet is shown in pastenew.avi
Bring your disk to the final exam, as you will have a problem requiring
deletion and insertion. If you know how to do this, the problem will take
only a few minutes to do.
| Everything is due by the Last Class. Nothing will be accepted late. |
Stock Market information:
- Market Beta for individual stocks
- NYSE Stock directory
- NASDAQ site
- AMEX
- Yahoo Links on Investment concepts
- BUDweiser and other symbol lookup at YAHOO
- to find history, click on historical prices.
- Stock Market Beta = volatility relative to the market, a measure of nondiversifiable risk. (definitions from Yahoo) Should be related to Return.
- Estimating Risk Parameters and Costs of Financing-- a chapter from Aswath Damodaran of NYU
- Examples from Class: Budweiser (Beta may be zero) and IBM (Beta >1) compared to S&P 500
- Download 5 years' worth of monthly prices from YAHOO for the S&P 500. there is a download to spreadsheet link at the bottom of the historical prices. open the file in EXCEL and calculate returns as (Pt-Pt-1)/Pt-1, based on adjusted closing prices.
- Do the same for a stock of your choice (avoid stocks others are doing)
- Re-sort the date from oldest to most recent data so that the time series charts are in the right direction.
- chart a time series for the two returns and estimate trend lines using the right-click chart options.
- Produce a scatterchart of the single stock returns vs. the S&P and estimate an intercept and linear slope with chart options.
- Conduct a Simple Regression procedure and see if you get a slope significantly different from zero. Comment on the slope and the Pvalue. This is known as Market Beta.
Exercise 6 -extra credit due Thursday April 28
Time series and Forecasting
powerpoint from the bookSeasonal data on KWH use Timseasn.xls
Some Really BAD Forecasts
Think for yourself.
How bad is unemployment right now? See historical and current unemployment statistics from the Current Population Survey Statistics . Here is data converted to EXCEL, unemp.xlsDid the economy take a dive after 9/11 or was the dip something that
started even before the current administration came into office?
Historical Nasdaq daily data in EXCEL
Historical Stock index data free from YAHOO:
Dow-Jones index monthly, 1928 to current djindex.xls
S&P 500 from 1982 to present spindex.xls
comments
or questions to rbanis (at) jinx.umsl.edu
