The marginal cost of a product can be thought of as the cost of producing one additional unit of output. for example, if the marginal cost of producing the 50th product is $6.20, it cost $6.20 to increase production from 49 to 50 units of output. suppose the marginal cost c (in dollars) to produce x thousand mp3 players is given by the function upper c (x )equals x squared minus 160 x plus 7800. a. how many players should be produced to minimize the marginal cost? b. what is the minimum marginal cost?