In the previous Problem Set question, we started looking at the cost function C ( ), the cost of a firm producing a items. An important microeconomics concept is the marginal cost, defined in (non-mathematical introductory) economics as the cost of producing one additional item. If the current production level is a items with cost C (x), then the cost of computing h additionial items is C (x + h). The average cost of those h items (C(Ith)-C(x)) As we analyze the cost of just the last item produced, this can be made into a mathematical model by taking the limit as h - 0, i.e. the derivative C (x). Use this function in the model below for the Marginal Cost function MC (x). Problem Set question: The cost, in dollars, of producing a units of a certain item is given by C(x) = 0.04x3 - 15x + 200. (a) Find the marginal cost function. MC (x) = (b) Find the marginal cost when 70 units of the item are produced. The marginal cost when 70 units are produced is $ Number (c) Find the actual cost of increasing production from 70 units to 71 units. The actual cost of increasing production from 70 units to 71 units is $ Number