A company manufactures mountain bikes. The research department produced the marginal cost X function C'(x) = 400 - 3,0x 900, where C'(x) is in 3' dollars and x is the number of bikes produced per month. Compute the increase in cost going from a production level of 300 bikes per month to 720 bikes per month. Set up a definite integral and evaluate it. The increase in cost is $