A hospital conducted a study of the waiting time in its emergency room. The hospital has a main campus, along with three satellite locations. Management had a business objective of reducing waiting time for emergency room cases that did not require immediate attention. To study this, a random sample of 15 emergency room cases at each location were selected on a particular day, and the waiting time (recorded from check-in to when the patient was called into the clinic area) was measured. The results are stored in ERWaiting.
a. At the 0.05 level of significance, is there evidence of a difference in the median waiting times in the four locations?
b. Compare the results of (a) with those of Problem 11.9 (a) on page 402.