Statista reports that the average monthly lease payment for an automobile is falling in the U.S. (Statista website, June 15, 2016), but does this apply to all classes of automobiles? Suppose you are interested in whether this trend is true for sport utility vehicles (SUVs). The file SUVLease contains monthly lease payment data for 33 randomly selected SUVs in 2015 and 46 randomly selected SUVs in 2016.
a. Provide and interpret a point estimate of the difference between the population mean monthly lease payments for the two years.
b. D evelop a 99% confidence interval estimate of the difference between the mean monthly lease payments in 2015 and 2016.
c. Would you feel justified in concluding that monthly lease payments have declined from 2015 to 2016? Why or why not?