Suppose that the weekly sales volume y (in thousands of units sold) depends on the price per unit of the product according to where p is in dollars. What is the rate of change in sales volume when the price is $20? Round your answer to three decimal places.

Question

Suppose that the weekly sales volume y (in thousands of units sold) depends on the price per unit of the product according to  where p is in dollars. What is the rate of change in sales volume when the price is $20? Round your answer to three decimal places. ​

Quizplus · Accepted Answer

Taking the derivative of the function gives:

y′=−0.006p+1.35

Plugging in p=20 gives:

y′=−0.006(20)+1.35=1.23

Therefore, the rate of change in sales volume when the price is $20 is 1.23 thousand units per dollar. Rounded to three decimal places, this is 1.230. The answer is choice C.

Suppose That the Weekly Sales Volume Y (In Thousands of Units