A4. In a random sample of 100 people, the correlation between amount of daily exercise and weight was found to be

.21. What would be the likely effect on the absolute value of the correlation coefficient under the following circumstances:

(a) The sample is restricted to people who weighed under 180 pounds.

(b) The sample is restricted to people who get virtually no daily exercise versus those who exercise at least 30 minutes a day.

(c) The mean sample weight is 150 pounds, and one person is added to the sample who weighs 275 pounds.