A stock analyst wondered whether the mean rate of return of financial, energy, and utility stocks differed

Question:

A stock analyst wondered whether the mean rate of return of financial, energy, and utility stocks differed over the past five years. He obtained a simple random sample of eight companies from each of the three sectors and obtained the five-year rates of return shown in the following table (in percent):

Financial Energy Utilities 10.76 12.72 11.88 15.05 13.91 5.86 17.01 6.43 13.46 5.07 11.19 9.90 19.50 18.79 3.95 3.44 8.1

(a) State the null and alternative hypotheses.
(b) Verify that the requirements to use the one-way ANOVA procedure are satisfied. Normal probability plots indicate that the sample data come from normal populations.
(c) Are the mean rates of return different at the a = 0.05 level of significance?
(d) Draw boxplots of the three sectors to support the results obtained in part (c).

Stocks
Stocks or shares are generally equity instruments that provide the largest source of raising funds in any public or private listed company's. The instruments are issued on a stock exchange from where a large number of general public who are willing...