ANOVA:

To examine the effects of pets and friends in stressful situations, researchers recruited 45 people to participate in an experiment. Fifteen of the subjects were randomly assigned to each of three groups to perform a stressful task alone (control group), with a good friend present, or with their dog present. Each subject's mean heart rate during the task was recorded. Test the appropriate hypotheses at the .05 significance level to decide if the mean heart rate differs between the groups.

Use the graph below and your statistical knowledge:

n Mean Std. Dev. Control 15 82.52 9.24 Pets 15 73.48 9.97 Friends 15 5 91.325 8.34