The National Retail Federation reported that college freshman spend more on back-to-school items than any other college group (USA Today, August 4, 2006). Sample data comparing the back-to-school expenditures for 25 freshmen and 20 seniors are shown in the data file Back to School.
a. What is the mean back-to-school expenditure for each group? Are the data consistent with the National Retail Federation's report?
b. What is the range for the expenditures in each group?
c. What is the interquartile range for the expenditures in each group?
d. What is the standard deviation for expenditures in each group?
e. Do freshmen or seniors have more variation in back-to-school expenditures?