Adriana Corporation manufactures football equipment. In planning for next year, the managers want to understand the relation between activity and overhead costs. Discussions with the plant supervisor suggest that overhead seems to vary with labor-hours, machine-hours, or both. The following data were collected from last year's operations. Month Labor-Hours Machine-Hours 720 1,354 715 1,408 675 1,526 740 1,444 1,589 755 1,587 740 1,382 725 1,304 715 1,458 790 1,551 680 1,288 715 1,610 Overhead Costs $ 102,774 103,778 109,847 108,254 116, 289 114,529 106,941 102,196 106, 378 113,146 102,437 115,800 Required: a. Use the high-low method to estimate the fixed and variable portions of overhead costs based on machine-hours. b. Managers expect the plant to operate at a monthly average of 1,400 machine-hours next year. What are the estimated monthly overhead costs, assuming no inflation