Given a cost function C(x) as C(x)=20+x−12x^2, calculate the marginal average cost when x=2, use this to approximate the average cost when x=3, and calculate the percentage error between this estimate...

Given a cost function C(x) as

calculate the marginal average cost when x=2, use this to approximate the average cost when x=3, and calculate the percentage error between this estimate and the actual cost when x=3. Give your answer as a percentage to the nearest integer. Do not include the percent symbol in your answer.