A hospital conducted a study of the waiting times in its emergency room at the main campus and three offsite locations. Studying only cases that did not require immediate attention, random samples of 15 were taken at each location on a particular day. The waiting times (from check-in to clinic visit) were measured with the results stored in ER Waiting.
(a) At the 0.05 level of significance, is there evidence of a difference in the mean waiting times in the four locations? State your null and alternative hypotheses. (Note: while the small sample size could justify use of the non- parametric Kruskal-Wallis rank test, assume normality and use the ANOVA test.
(b) Use the Tukey-Kramer procedure tom see which ones are different.