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 Overhead Costs 730 710 690 745 785 760 745 730 715 795 680 705 1,351 1,406 1,528 1,452 1,585 1,579 1,392 1,317 1,446 1,553 1,296 1,614 S 102,642 103,799 109,853 108,399 116,248 114,442 106,990 102,094 106,331 113,007 96,960 108,885 4 7 9 10 12 Required a. Use the high-low method to estimate the fixed and variable portions of overhead costs based on machine-hours. (Round "Variable cost" answer to 2 decimal places.) Variable cost (per machine hour) Fixed cost b. Managers expect the plant to operate at a monthly average of 1,600 machine-hours next year. What are the estimated monthly overhead costs assuming no inflation? (Round Variable cos?" answer to 2 decimal places.) Overhead costs