The General Electric service department believes that the median time for a service call should be 30 or fewer minutes.To test this,the following random sample of service times was collected: Given that the managers do not wish to make the assumption that the population is normally distributed,the appropriate statistical test for testing about service times is:
A)the t-test.
B)the Kruskal-Wallis test.
C)the Wilcoxon signed rank sum test.
D)the F-test.

Question

The General Electric service department believes that the median time for a service call should be 30 or fewer minutes.To test this,the following random sample of service times was collected:  Given that the managers do not wish to make the assumption that the population is normally distributed,the appropriate statistical test for testing about service times is:
A)the t-test. 
B)the Kruskal-Wallis test. 
C)the Wilcoxon signed rank sum test. 
D)the F-test.

Quizplus · Accepted Answer

Since the population distribution is not assumed to be normal, the appropriate test is a non-parametric test. The Wilcoxon signed rank sum test is used to test whether two independent samples come from populations with equal medians. Thus, it is the best choice for testing whether the median service time is 30 or fewer minutes in this case.

The General Electric Service Department Believes That the Median Time