STAT 280 fall 2005
Lab 2
Lab 2 is due one week from your lab to your TA. Your TA means the TA who is
instructing the lab you have registered for. Labs my be turned in to your TA’s mailbox
located in DH 1092 or handed in to him/her in person after the lab. E-mail submissions
are not accepted.
Labs are to be written up in legible reports with all graphs labeled. It is possible to insert
graphs and spreadsheets into a Microsoft word document, but this is not necessary.
The file name of the data is DataSet2.XLS available on the courses website. This data
set is also on the CD found attached to the back cover of your textbook. On the CD this
data is called CS.XLS. In the CD Drive, click the PCDataSets folder, then the Excel
folder, then the Appendix folder, and you will see the CS.XLS file. Double-click to
open this file in Excel.
You also need to make sure the Analysis ToolPak add-in is installed on Excel. In Excel,
go to Tools Add-Ins and make sure Analysis ToolPak is checked and click Ok. For
this lab you will also need to make sure the S-Plus option is checked. The S-Plus option
is found under the Analysis ToolPak option.
Codebook [i.e. what the columns mean in the data set]
1. OBS – this is the number each student was assigned from 1 to 224.
2. GPA – the student’s GPA for their first three semesters of college (4-point scale).
3. HSM– average high school grade in math
4. HSS – average high school grade in science
5. HSE – average high school grade in English
6. SATM – SAT math score
7. SATV – SAT verbal score
8. SEX – 1 for male, 2 for female
Objective
The purpose of this lab is to help you understand the normal distribution and how to
identify normal distributions from graphs. You should also learn how to make
comparisons between sample populations using graphs. Finally we wish to look at
relationships between variables by exploring correlation.
Tasks
1. In Lab1 we calculated probabilities using excel, we will revisit that technique here.
