Consider again the one-way ANOVA hypothesis test described in Problem 10. Suppose that we are interested in comparing the mean starting salary of accounting students with that of each of the other three majors (i.e., marketing, finance, and management). Recall that the relevant data are provided in the file P12_10.XLS. 

a. Which method for generating confidence intervals for mean differences is most appropriate in this situation? Explain your choice. 

b. Apply the method identified in part a to estimate the mean differences of interest. Briefly interpret your findings.

Data from in Problem 10

Do graduates of undergraduate business programs with different majors tend to earn disparate average starting salaries? Consider the data given in the file P12_10.XLS. 

Is there any reason to doubt the equal-variance assumption made in the one-way ANOVA model in this particular case? Support your response to this question.

Assuming that the variances of the four underlying populations are indeed equal, can you reject at the 10% significance level that the mean starting salary is the same for each of the given business majors? Explain why or why not.

Generate90% confidence intervals for all pairs of differences between means. Which of these differences, if any, are statistically significant at the 10% significance level?