The cost (in dollars) of producing x units of a certain commodity is C(X) = 2000 + 7X + 0.1x2. (a) Find the average rate of change of C with respect to X when the production level is changed from X = 100 to the given value. (Round your answers to the nearest cent.) (i) X: 105 (II) X: 101 (b) Find the instantaneous rate of change of C with respect to X when X = 100. (This is called the marginal cost.)