Table 13-5 number of workers output 0 0 1 10,000 2 19,000 3 27,000 4 32,000 5 35,000 6 36,000 refer to table 13-5. assume that fixed costs are $500, and variable costs are $100 per worker. for this firm, what are the shapes of the production function and the total-cost curve? a. the production function is increasing at an increasing rate, whereas the total-cost function is increasing at a decreasing rate. b. both the production function and total-cost curve are increasing at an increasing rate. c. both the production function and total-cost curve are increasing at a decreasing rate. d. the production function is increasing at a decreasing rate, whereas the total-cost function is increasing at an increasing rate.