The file Sedans contains the overall miles per gallon (MPG) of 2012 family sedans:
38 24 26 21 25 22 24 34 23 20 37 22 20 33 22 21
Source: Data extracted from "Ratings," Consumer Reports, April 2012, pp.31.
a. Construct a 95% confidence interval estimate for the population mean MPG of 2012 family sedans, assuming a normal distribution.
b. Interpret the interval constructed in (a).
c. Compare the results in (a) to those in Problem 8.20(a).