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 At units $ 8 3,400 At 2,000 units $ 10,400 At 4,000 units $ 20,800 3,400 Direct materials 6,400 3,400 12,800 Rent on factory building 1,400 1,400 1,400 Salesperson compensation Factory supervisor salary Factory utilities Insurance on factory building 3,400 3,400 4,400 4,400 4,400 4,400 140 540 740 900 900 900 Direct labor Depreciation on factory equipment Direct materials Rent on factory building Salesperson compensation Factory supervisor salary Factory utilities Insurance on factory building