## Calculus Concepts: An Informal Approach to the Mathematics of Change 5th Edition

a. We see the ticket price is set at 65 dollars by looking at $f(65)$ then we see that the weekly profit is 15,000 because it says that $f(65) = 15$ and the units of measure are thousand dollars. b. We see that the ticket price is set at 65 dollars by looking at $f'(65)$, then we see it is prime so it means that we are looking at the change (in sales) per dollar. We get 1.5 thousand from looking at $f'(65)= 1.5$ and know that the units are thousand dollars. c. We see that the ticket price is set at 90 dollars by looking at $f'(90)$, then we see it is prime so it means that we are looking at the change (in sales) per dollar. We get 2 thousand from looking at $f'(90)= 2$ and know that the units are thousand dollars.