the zig-zag company manufactures zippers for many clothing manufacturers. costs for the year were direct materials, $5,000; indirect materials, $1,600; direct labor, $12,000; and indirect labor, $4,000. additional expenses for the year were factory utilities $3,500; depreciation of factory equipment, $1,300; advertising expense, $900; delivery expense on sales to customers, $1,700; and property taxes on factory buildings, $5,200. which amount is the company's manufacturing overhead for the year?