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 =73.3, s=5. It is well known that the mean resting heart rate of adults is 71 beats per minute.

a. Calculate the value of the test statistic.

b. Make the appropriate conclusion.