Chapter 12, Problem 10PT4

To determine

To find: one of the following tests of significance may reasonably be used to assess if the presumption of the adjusters is correct on the basis of given information.

Answer to Problem 10PT4

I, II, and III

Explanation of Solution

Given:

  

Definitely this issue is a paired T-test as each experiment is matched by car.

Typically, the two-sample T test is used where the results are not matched, so these two samples can be viewed as not matched and the study should be performed this way. In this case, the standard error would typically be much larger, which wouldn't be achieved.

The third test is very tricky. Most books wouldn't recommend doing it that way, but don't think it's possible for the author to do it that way. There should dummy code the cars and stores, and check to see if the store related dummy vector slope is 0 or not. This is not a common thing to do but yet a valid way to tackle this issue.

The author leaves this issue unclear, but from a theoretical point of view, all three experiments should be performed to resolve this issue.

Hence, the correct option is (e)