The total cost (in dollars) of manufacturing x auto body frames is C(x) = 40,000 + 500x. (A) Find the average cost per unit if 400 frames are produced. (B) Find the marginal average cost at a production level of 400 units. (C) Use the results from parts (A) and (B) to estimate the average cost per frame if 401 frames are produced. The total cost (in dollars) of producing x food processors is C(x) = 2500 + 80x - 0.1 x2. (A) Find the exact cost of producing the 81st food processor. (B) Use the marginal cost to approximate the cost of producing the Bist food processor. The total cost (in dollars) of manufacturing x auto body frames is C(x) = 40,000 + 600x. (A) Find the average cost per unit if 250 frames are produced. (B) Find the marginal average cost at a production level of 250 units. (C) Use the results from parts (A) and (B) to estimate the average cost per frame if 251 frames are produced