(2 points) A manufacturer can produce digital recorders at a cost of 50.dollars each. It is estimated that if the recorders are sold for p dollars apiece, consumers will buy q = 120 - p recorders each month. a) Express the manufacturer's profit P as a function of q. P = b) What is the average rate of profit obtained as the level of production increases from q = 0 to q = 10? The average rate of profit is dollars per unit. c) At what rate is profit changing when q = 10 recorders are produced? The rate at which the profit is changing is dollars per unit