Chapter 26, Problem 2E

a)

To determine

To state which test would be appropriate for given situation.

Answer to Problem 2E

Chi-square goodness of fit.

Explanation of Solution

Given:

Is the quality of a car affected by what day it was built? A car manufacturer examines a random sample of the warranty claims filed over the past two years to test whether defects are randomly distributed across days of the work week.

Here, researcher wants to check whether distribution is uniform. Therefore, there is one variable so Chi-square goodness of fit test would be appropriate to use.

b)

To determine

To state which test would be appropriate for given situation.

Answer to Problem 2E

Other test.

Explanation of Solution

Given:

A medical researcher wants to know if blood cholesterol level is related to heart disease. She examines a database of 10,000 patients, testing whether the cholesterol level (in milligrams) is related to whether or not a person has heart disease.

The situation does not contain any count as cholesterol level is in milligrams. Hence, there should be other test used.

c)

To determine

To state which test would be appropriate for given situation.

Answer to Problem 2E

Chi-square test for independence.

Explanation of Solution

Given:

A student wants to find out whether political leaning (liberal, moderate, or conservative) is related to choice of major. He surveys 500 randomly chosen students and performs a test.

The researcher is interested to check whether the variables are dependent. Hence, Chi-square test for independence would be appropriate to use.