The Personnel Manager of a large corporation believes that regular physical exercise leads to a lower resting pulse rate (and so healthier staff). Data was collected on resting pulse rate and whether or not people exercised regularly for a random sample of 22 employees of the corporation. The results are given below. Exercise regularly 62 72 60 63 75 64 60 52 64 80 68 64 Do not exercise regularly 72 84 66 72 62 78 84

Studies indicate that excessive noise at night can affect weight gain. One study of n = 127 rats compared the weight gain of rats exposed to excessive noise at night and the weight gain of rats in a quiet night environment. Sample statistics for the study are given in the table below. Use this information to determine if there is significant evidence that weight gain of rats exposed to excessive noise at night is different on average than weight gain of rats in a quiet night environment.        Excessive noise at night environment  (Group 1)   Quiet night environment  (Group 2) Sample mean (grams) 22.4 19.9 Sample standard deviation (grams) 6.4 3.8 Observations/Sample size 69 58       The 95% confidence interval for the difference (Group 1 – Group 2) in weight gain of rats exposed to excessive noise at night and rats in quiet night environment is (0.7g, 4.3g). Interpret this confidence interval in one or two sentences.

Swearing is a common, almost reflexive, response to pain. Whether you knock your shin into the edge of a coffee table or smash your thumb with a hammer, most of us respond with a streak of obscenities. One question, however, is whether swearing has any effect on the amount of pain that you feel. To address this issue, Stephens, Atkins, and Kingston (2009) conducted an experiment comparing swearing with other responses to pain. In the study, participants were asked to place one hand in icy cold water for as long as they could bear the pain. Half of the participants were told to repeat their favorite swear word over and over for as long as their hands were in the water. The other half repeated a neutral word. The researchers recorded how long each participant was able to tolerate the ice water. After a brief rest, the two groups switched words and repeated the ice water plunge. Thus, all the participants experienced both conditions (swearing and neutral) with half swearing on their first…

A scientist is studying the effect of a new type of exercise program on cardiovascular health. The scientist randomly assigns individuals to either the exercise program or a control group. The scientist wants to determine if the exercise program has a statistically significant effect on cardiovascular health. The scientist monitors cardiovascular health by measuring the blood pressure of each individual.