To:  sbaker@odu.edu

From:  Thomas Meyer
tmeyer@ph.vccs.edu
276 656-0283
Patrick Henry Community College

Subject:  Statistics - w/  Dr.Spencer Baker - Homework Assignment #4, Ch 11 - Problem 20, page281.

Date: March 24, 2004

The algorithm for answering the following questions is different from that suggested in the text on page 277 because our version of SPSS does not have a statistics menu.

In this problem, use the following procedure:
 

1.  Get the data

2.  Manipulate the data

To find the 95% (and then the 99%) confidence interval for the mean for a variable:
(Refer to textbook instruction page 277 if necessary, keeping in mind that our version of SPSS does not have the menu called Statistics))
Having loaded the data
Click Analyze menu and choose Descriptive Statistics
Click Explore
Select the variables wanted and move them into the Variables box
Click the box called Statistics
Insert 99% (or accept 95% as a default)
Click OK.

3.  Do something with the data

Right-click the output
Select copy object
Paste the copied object into FrontPage  (Before you paste the object, right-click and read the"results coach")
Save your work


Question:
Use the SPSS program and SPSS data bank to complete this exercise.  For the data set career.sav. find the 95% and 99% confidence intervals for the following variables: confidence in doing mathematics (confmath) and anxiety about doing mathematics (anxiety).

Answer:

 

The following table contains the 95% confidence intervals (lower and upper boundaries) for the mean:

                               At a glance, we see that:                                 

Anxiety About Doing Math, 95% confidence interval for the mean is 40.50  to 43.40

Confidence in Doing Math, 95% confidence interval for the mean is 43.85 to 46.53

 

The following table contains the 99% confidence intervals (lower and upper boundaries) for the mean:

                               At a glance, we see that:                                 

Anxiety About Doing Math, 99% confidence interval for the mean is 40.04  to 43.86

Confidence in Doing Math, 99% confidence interval for the mean is 43.42 to 46.96

 

 

filename: StatHW3Ch11Prob20page306TomMeyer.doc

Tom Meyer

Thomas Meyer