4x - 7 The total cost (in hundreds of dollars) to produce x units of perfume is C(x)= 2x + 3 (a) Find the average cost function. (b) Find the marginal average cost function. (c) Find the average cost and the marginal average cost for a production level of 30 units. Interpret your results. (a) The average cost function is C(x) = (b) The marginal average cost function is C'(x) = (c) The average cost for 30 units is $ per unit. The marginal average cost for 30 units is $ (Round to the nearest cent as needed.) Interpret your results. When 30 units are produced, the average cost is $ per unit and the average cost is at a rate of about $ per unit. (Round to the nearest cent as needed.)