Question3. Psychologists were interested in the physiological changes that occur when a person laughed. The subjects in the study watched videos to encourage laughter. While the subjects were laughing, the researchers measured the subject's pulse. In a sample of 90 subjects, the mean heart rate was 73.5 beats per minute (bpm) with standard deviation 6 bpm . The mean resting heart rate of the population of all adults is known to be 71 bpm with standard deviation 7.5 bpm . The researchers wish to determine if the mean heart rate is elevated during laughter. In a previous example, we determined that the z -test for the mean should be conducted. a. Set up the null and alternative hypothesis for this test. b. Calculate the value of the test statistic. c. Find the p-value. d. At the $\alpha=0.05$ level of significance, make a decision whether to reject $\mathrm{H}_{0}$. e. Can it be determined that the mean heart rate is elevated during laughter?