(a) you have data for many years on the average price of a barrel of oil and the average retail price of a gallon of unleaded regular gasoline. if your desire is to predict the price of gasoline, the explanatory variable on the x -axis: a. is the price of gasoline. b. can be either oil price or gasoline price. c. is the price of oil. d. none of the above.
(b) what are all the values that a correlation r can possibly take? a. 0 ≤ r ≤ 1 b. -1 ≤ r ≤ 1 c. r ≥ 0 d. none of the above.
(c) in a scatterplot of the average price of a barrel of oil and the average retail price of a gallon of gasoline, you expect to see: a. a positive association. b. a negative association. c. very little association. d. none of the above.