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 12 - Problem 10, page 306.

Date: March 26, 2004

Question:
Suppose the sample means are given below for the corresponding examples in Exercise 9.  What decision should you make about the null hypothesis in each case?

a. Sample "Xbar" = 92

b. Sample "Xbar"  = 550

c. Sample "Xbar"  = 18

d.  Sample "Xbar"  = 20

e. Sample "Xbar"  = 60

f.  Sample "Xbar"  = 104

Answer:

A.  Since Sample "Xbar" = 92 is neither greater than 109.8 nor less than 90.2, (critical values resulting from alpha = .05 on a two-tail test), we fail to reject the null hypothesis that Ho: mu =100.

B.  Since Sample "Xbar"  = 550is greater than 546.52, (critical value resulting from alpha = .01 on a one-tail test), we reject the null hypothesis that Ho: mu <=500.

C.  Since Sample "Xbar"  = 18 is greater than 16.62, (though not less than or equal to 15.38), (critical values resulting from alpha = .01 for a two-tail test, we reject the null hypothesis that Ho: mu = 16.

D.  Since Sample "Xbar"  = 20 is not less than or equal to 18.16 (critical value resulting from an alpha = .05 for a one-tail test), we fail to reject the null hypothesis that Ho: mu >= 18.8

E.  Since Sample "Xbar"  = 60 is not greater than or equal to 66.79 nor less than or equal to 59.61 (critical values resulting from an alpha = .001 in a two-tail test), we fail to reject the null hypothesis that Ho: mu = 63.2.

F.  Since Sample "Xbar"  = 104 is not greater than nor equal to 104.11, (critical value resulting from an alpha = .05 fro a one-tail test), we fail to reject the null hypothesis that Ho: mu <= 100.

filename: StatHW3Ch12Prob10page306TomMeyer.doc

Tom Meyer

Thomas Meyer