Stocks may be categorized by sectors. Go to www.pearsonhighered.com/sullivanstats to obtain the data file 11_3_17 using the file format of your choice for the version of the text you are using. The data represent the one-year rate of return (in percent) for a sample of consumer cyclical stocks and industrial stocks for the period December, 2013, through November, 2014. Note: Consumer cyclical stocks include names such as Starbucks and Home Depot. Industrial stocks include names such as 3M and FedEx.

(a) Draw side-by-side boxplots of one-year rate of return by sector. Does there appear to be a difference in the one-year rate of return for these two sectors?

(b) Explain why the methods of this section may be used to test whether the mean rate of return for the two sectors differ.

(c) Test whether the mean one-year rate of return for consumer cyclical stocks is different from that of industrial stocks at the a = 0.05 level of significance.

(d) Construct a 95% confidence interval for the mean difference in rate of return between industrial stocks and consumer cyclical stocks. Interpret the interval.