Answer :

upandover

To find the rate of change, also known as the slope, we can use the slope formula with these two given points.

Point 1: (20, 25)

Point 2: (50, 40)

(40 - 25) / (50 - 20)

15 / 30

0.5

The rate of change of this function is $0.50 / lb.

Hope this helps!! :)