4. Suppose that the demand equation for a monopolist's product is p =4002x and the average cost function is 5(x) = 0.2): +4+ 5E, where x is the number of units, and both x p and 20:) are expressed in dollars per unit. a. Determine the level of output ( i.e. nd the value of x l at which profit is maximized. b. Determine the price at which maximum profit occurs. * c. Determine the maximum prot