You are interested in finding a 98% confidence interval for the average commute that non-residential students have to their college. The data below show the number of commute miles for 12 randomly selected non-residential college students.

28

23

23

16

16

10

7

12

27

21

27

18

a. To compute the confidence interval use a ? t z distribution.

b. With98% confidence the population mean commute for non-residential college students is between and miles.

c.If many groups of 12 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. About percent of these confidence intervals will contain the true population mean number of commute miles and about percent will not contain the true population mean number of commute miles.