1. A researcher is interested in finding a 98% confidence interval for the mean number minutes students are concentrating on their professor during a one hour statistics lecture. The study included 99 students who averaged 40.9 minutes concentrating on their professor during the hour lecture. The standard deviation was 10.5 minutes. Round answers to 3 decimal places where possible.

b. With98% confidence the population mean minutes of concentration is between____ and _____ minutes.

c.If many groups of 99 randomly selected members are studied, then a different confidence interval would be produced from each group. About _________ percent of these confidence intervals will contain the true population mean minutes of concentration and about ______percent will not contain the true population mean minutes of concentration.

2. You are interested in finding a 90% confidence interval for the average commute that non-residential students have to their college. The data below show the number of commute miles for 14 randomly selected non-residential college students. Round answers to 3 decimal places where possible.

22

16

25

17

9

12

14

5

11

7

20

8

23

15

b. With90% confidence the population mean commute for non-residential college students is between _____and _______miles.

c.If many groups of 14 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.