6. A study was conducted to examine the effect of pets in stressful situations. Fifteen subjects were randomly assigned to each of three groups to do a stressful task alone (the control group), with a good friend present, or with their dog present. The subject's mean heart rate (in beats per minutes) during the task is one measure of the effect of stress. The data has is the mean heart rates during stress with a pet (P), with a friend (F) and for the control group (C). Pet 69.169 Control Friend 80.369 99.692 87.446 83.4 70.169 102.15 90.015 4 75.985 99.046 80.277 75.477 88.015 68.862 86.446 87.231 92.492 64.169 91.754 91.354 97.538 100.87 87.785 7 85 101.06 77.8 2 72.262 62.646 81.6 58.692 84.738 89.815 79.662 84.877 98.2 69.231 73.277 76.908 69.538 84.523 86.985 70.077 70.877 97.046 65.446 This data is in the homework and calendar website called "Stress". a. Make a side by side box plot of the heart rates by the three groups. To do this in R use: plot(Rate Group,data=Stress) Does there seem to be a difference in the heart rates of the three groups? Do any of the groups show outliers or extreme skewness? b. We want to test if there is a difference in the mean heart rates for the three groups. Give the null hypothesis of this test. c. Does the data suggest that there is a difference among the three groups? Use a = 0.05. d. If there seems to be a difference, complete a Bonferroni pairwise test to determine which or if all the means are different from each other.