Following are costs for eight different items. Costs are shown for three different levels of units produced and sold. Classify each of the eight cost items as either variable, fixed, or mixed. Costs for Different Levels of Units Produced and Sold Direct labor Depreciation on factory equipment Direct materials Rent on factory building Salesperson compensation Factory supervisor salary Factory utilities Insurance on factory building At 0 units At 2,000 units At 4,000 units $0 $ 10,600 $ 21,200 3,600 3,600 0 3,600 13,200 6,600 1,600 1,600 4,600 4,600 1,600 3,600 4,600 160 950 3,600 4,600 560 950 760 950 ok ences Direct labor Depreciation on factory equipment Direct materials Rent on factory building Salesperson compensation Factory supervisor salary Factory utilities Insurance on factory building