A study was conducted to see whether two types of cars, A and B, took the same time to parallel park. Seven drivers were randomly obtained and the time required for each of them to parallel park each...

A study was conducted to see whether two types of cars, A and B, took the same time to parallel park. Seven drivers were randomly obtained and the time required for each of them to parallel park each of the 2 cars was measured. The results are listed in the following table.

Is there evidence that the time required to parallel park the two types of car are, on average, different?

(a) Test at α = 0.05 using the paired T test. What assumptions are needed for the validity of this test? Comment on the appropriateness of the assumptions for this data set.

(b) Test at α = 0.05 using the signed-rank test.