The total cost to produce x boxes of cookies is C dollars, where C = 0.0001x3 0.04x2 + 2x + 300. In t weeks, production is estimated to be x = 1600 + 100i: boxes. (a) Find the marginal cost C'(x). . . . . . dC dC dx . . . . (b) Use Leibniz s notation for the chain rule, _ = _ - _, to nd the rate With respect to time t that the cost is changing. dt dx dt =:| dt (c) Use the results from part (b) to determine how fast costs are increasing (in dollars per week) when t = 2 weeks. I:] dollars per week