Answer:
the graph will describe 13x+15 if the cost per audio book goes up by $1.00.
Step-by-step explanation:
This happens because the coefficient to x is 12 before the change. If the change is the cost per audio book going up by one dollar, the coefficient changes to 13. The initial joining fee is the same ($15.00).
What about it that is not a question
You just add the values for volunteers that worked 16-20 hours and 21-25 hours which would be 50 + 10 = 60. So the total number of volunteers that workers more than 15 hours is 60.
