Class 5. Q.9

Suppose that the total cost C(x) in thousands of dollars, for manufacturing x a certain type of boat per year is give by $C(x)=800 + 30x - \frac{x^2}{4}$

(a)

Find the marginal cost of production

(b)

Find the marginal cost of production at 20 boats, and interpret the results.

(c)

Find the actual cost of producing the 21^st boat, and compare this cost with result in (b).

(d)

Find $C^{\prime}(40)$, and interpret the result.