Answer:
Step-by-step explanation:
rate of change is the slope of the line
plot the data and calculate the slope or simple find the delta cost divided by the delta people
(cost x - cost y) / (people x - people y) = rate of change
you can pick any cost as long as you use the coresponding people
(19.75 - 7.90) / (5 - 2) = rate of change
( 11 .85) / (3) = rate
3.95 = rate
try it for different cost and people and see if you get the same rate, it looks linear to me
