Answer:
$25.5 per hour.
Step-by-step explanation:
The function C(x) = 25.50x + 50 ........ (1) models the total cost for a cleaning company to clean a house, where x is the number of hours it takes to clean the house.
Now, from the linear equation it is clear that the change in cost of cleaning from 3 hours and 9 hours are respectively {From equation (1)}
C(3) = 25.5 × 3 + 50 = $126.5 and
C(9) = 25.5 × 9 + 50 = $279.5
Therefore, the average rate of change of the function between 3 hours and 9 hours will be = [tex]\frac{\textrm {Change in price of cleaning}}{\textrm {Change in hours}}[/tex]
= [tex]\frac{279.5 - 126.5}{9 - 3}[/tex]
= $25.5 per hour. (Answer)
