(a) For a biology project, you measure the weight in grams and the tail length in millimeters of a group of mice. The correlation is r = 0.2. If you had measured tail length in centimeters instead of millimeters, what would be the correlation? (There are 10 millimeters in a centimeter.) A. 0.2/10 = 0.02 B. 0.2 C. (0.2)(10) = 2 D. None of the above.
(b) A study found a correlation of r = -0.61 between the gender of a worker and his or her income. You may correctly conclude A. women earn more than men on average. B. women earn less than men on average. C. an arithmetic mistake was made. Correlation must be positive. D. this is incorrect because r makes no sense here. E. None of the above.
You can earn partial credit on this problem.