Variable Costs Fixed Costs per Month Direct material $8.00/unit Supervisory salaries $21,420 Direct labor 3.50/unit Factory depreciation 13,230 Variable overhead 1.80/unit Other factory costs 3,860 During the period, Marx produced 16,380 units and incurred the following costs: Variable Costs Fixed Costs per Month Direct material $129,150 Supervisory salaries $22,250 Direct labor 63,000 Factory depreciation 11,970 Variable overhead 28,980 Other factory costs 4,330