A firm hires four workers and rents 10 capital units for a operationg period. It produces 12,000 units. If it had doubled its use of labor and capital, production would have been 24,000 units. Does the firm have constant, increasing, or decreasing returns to scale? Why? If wages are $20,000 per person per operating period and capital units for $3,000 per unit per operating period, calculate the average cost of producing 12,000 units and the average cost od producing 24,000 units.