A firm in a purely competitive industry has a typical cost structure. The normal rate of profit in the economy is 5 percent. This firm is earning $15 on every $150 invested by its founders. Instructions: Enter your answers as whole numbers. a. What is its percentage rate of return? percent. b. Is the firm earning an economic profit? . If so, how large? Percent. c. Will this industry see entry or exit? . d. What will be the rate of return earned by firms in this industry once the industry reaches long-run equilibrium? percent.