Q. A researcher wants to study the effect of regular exercise on cholesterol levels. The researcher compares the cholesterol levels of 50 people who belong to a local gym and exercise regularly with the cholesterol levels of 50 people from the community who did not exercise regularly. The cholesterol levels of the members of the gym were substantially lower. The researcher can conclude that

A.belonging to a gym reduces cholesterol level. B.exercising regularly reduces cholesterol level.

C.members of a local gym who exercised regularly had lower cholesterol levels than those in the community who did not exercise regularly.

Q. All but one of the following statements contain a blunder. Which one does not contain a blunder?

A."There is a correlation of r = 0.54 between the position a football player plays and his or her weight."

B."The correlation between amount of fertilizer and yield of tomatoes was found to be r = 0.33."

C."The correlation between the gas mileage of a car and its weight is r = 0.71 gallon-pounds."