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

As the population distribution is unknown, non-parametric tests should be used. The Wilcoxon signed rank sum test is appropriate for comparing the median of a single sample to a hypothesized median. Therefore, the Wilcoxon signed rank sum test is the best choice for testing about service times.

The General Electric Service Department Believes That the Median Time