13. For a set of X values and Y values, if X increases, Y increases. Thus, the correlation between X and Y is:

a. Positive

b. Negative

c. No correlation

14. Some researchers believed that there is association between the size of plates people use and the amount of food people eat. Image that a researcher recorded the diameter of dinner plates (measured in millimeters) and the amount of food (measured in grams) people consumed. She found that the correlation between these two was .48. Had she measured the dinner plates in cm instead, what would the correlation have been?

a. 0.24

b. 0.92

c. 4.8

d. 0.048

e. 0.48

15. If X and Y are perfectly and positively correlated, the correlation should be:

a. 1.0

b. 0.0

c. 0.5

d. -1.0