Rick Martin is the manager of a firm that produces an output that currently sells at $ 24 per unit. The firm uses only machinery and equipment, labor to produce its output. The rental rate on machinery and equipment is $ 240 per unit and the wage rate is $ 216 per worker. The firm is currently producing 124 units of its output. The firm is currently operating in the short run, renting 4 units of machinery and equipment, and employing 9 workers. Rick is considering whether he should change the current production level. He knows that the marginal product of labor from the last worker hired is 4 . What is the firm ' s total cost at the current level of output