Answer:
PART A
The amount of snowfall and number of trucks is proportional.
Because the increase in snowfall, increases the number of trucks sent out as read from the table.
PART B
Let the number of tracks be x
By linear extrapolation, we get
inches | 12 | 18 | 23
trucks | 30 | 45 | x
(23 - 12)/(x - 30) = (18 - 12)/(45 - 30)
(11)/(x - 30)=6/15
11×15 = 6(x - 30)
165 = 6x - 180
6x = 165 + 180
6x = 345
x = 57.5
x = 58 trucks
Hence, 58 trucks were sent out.