The cost of producing x thousand copies of HamletA????1s

The cost of producing x thousand copies of HamletA????1s second album, What dreams may come, is (1/127)x^2 + 13 thousand dollars and the price at which each of these x thousand copies 127 will be sold is p(x) = 5(2x + 12)/(x +3) dollars

(a) Find the marginal cost and the marginal revenue.

(b) Estimate the cost of producing the fourth batch of 1000 copies of the album using the marginal cost, rounded to the nearest cent.

(c) Find the actual cost of producing the fourth batch of 1000 copies of the album, rounded to the nearest cent.

(d) Estimate the revenue from the sale of the fourth batch of 1000 copies of the album using the marginal revenue, rounded to the nearest cent.

(e) Find the actual revenue from the sale of the fourth batch of 1000 copies of the album, rounded to the nearest cent.