Researchers investigated the physiological changes that accompany laughter. Ninety subjects (18-34 years old) watched film clips designed to evoke laughter. During the laughing period, the researchers measured the heart rate (beats per minute) of each subject, with the following summary results: x overbarxequals=73.773.7, sequals=44. It is well known that the mean resting heart rate of adults is 7171 beats per minute. Complete parts a through d below.