Researchers investigated the physiological changes that accompany laughter. Ninety subjects(18-34 yearsold) watched film clips designed to evoke laughter. During the laughingperiod, the researchers measured the heart rate(beats perminute) of eachsubject, with the following summaryresults: x=73.8, s=8. It is well known that the mean resting heart rate of adults is 71 beats per minute. Complete parts a through d below.

Set up H0 and Ha for testing whether the true mean heart rate during laughter exceeds 71 beats per minute.

A.

H0: =71

Ha: 71

B.

H0: 71

Ha: =71

C.

H0: =71

Ha: >71

D.

H0: =71

Ha: <71

If =0.10, find the rejection region for the test. Choose the correct answer below.

A.

z>1.645

B.

z>1.645 or z<1.645

C.

z<1.645

D.

z<1.28

E.

z>1.28 or z<1.28

F.

z>1.28

Calculate the value of the test statistic.

z=

(Round to two decimal places asneeded.)

Make the appropriate conclusion. Choose the correct answer below.

A.

Reject H0. There is insufficient evidence at the =0.10 level of significance to conclude that the true mean heart rate during laughter exceeds 71 beats per minute.

B.

Reject H0. There is sufficient evidence at the =0.10 level of significance to conclude that the true mean heart rate during laughter exceeds 71 beats per minute.

C.

Donotreject H0. There is sufficient evidence at the =0.10 level of significance to conclude that the true mean heart rate during laughter exceeds 71 beats per minute.

D.

Donotreject H0. There is insufficient evidence at the =0.10 level of significance to conclude that the true mean heart rate during laughter exceeds 71 beats per minute.