Chapter 16, Problem 28CE

Instructions: In all exercises, you may use a computer package (e.g., MegaStat, Minitab) or show Excel calculations in a worksheet, depending on your instructor’s wishes. Include relevant output or screen shots to support your answers. If you do the calculations yourself, show your work. State the hypotheses and give the test statistic and its two-tailed p-value. Make the decision. If the decision is close, say so. Are there issues of sample size? Is non-normality a concern?

The waiting time (in minutes) for emergency room patients with non-life-threatening injuries was measured at four hospitals for all patients who arrived between 6:00 and 6:30 p.m. on a certain Wednesday. The results are shown below. Research question: At α = .05, are the median waiting times the same for emergency patients in these four hospitals?