The cost, c, to produce b baseball bats per day is modeled by the function c(b) = 0.06b2 – 7.2b + 390. what number of bats should be produced to keep costs at a minimum?

a. 27 bats
b. 60 bats
c. 174 bats
d. 390 bats

To determine the number of bats that should be produced for the minimum cost, differentiate the given equation and equate to zero.
                             dC(b) / dt = (0.06)(2)b - 7.2
                                    0 = 0.12b - 7.2
The value of b from the derived equation is 60. Therefore, the company should produced 60 bats for the minimum cost. Thus, the answer is letter B.