Current year
number of bushels price of corn
3 24
6 48
9 72
12 96
15 120
18 144
previous year
number of bushels price of corn (dollars)

3 21
6 42
9 63
12 84

part a: describe in words how you can find the rate of change of a bushel of corn in the current year, and find the value. (5 points)
part b: how many dollars more is the price of a bushel of corn in the current year than the price of a bushel of corn in the previous year? show your work. (5 points)