Questions 15 to 17 are based on the following information: Many people often use loud music to get themselves motivated during physical exercises. Eight subjects listened to the same music once at a standard soft volume and once at a standard loud volume. In both cases the heart rate (beats per minute) was measured. The following data was recorded: Subject 2 3 4 5 6 7 8 standardsoftvolume 79.2 72.5 75.0 75.0 80.0 79.5 78.5 standard loud volume 95.5 89.5 90.3 92.0 97.01012 -13 Difference -16.3 -17 -15.3 -17 -17 -22.7