Troy Engines, Limited, manufactures a variety of engines for use in heavy equipment. The company has always produced all of the parts for its engines, including the carburetors. An outside supplier offered to sell one type of carburetor to Troy Engines, Limited, for a cost of $30 per unit. To evaluate this offer, Troy Engines, Limited, summarized the cost of producing the carburetor internally as follows: Per Unit 12,000 Units Per Year Direct materials $ 12 $ 144,000 Direct labor 8 96,000 Variable manufacturing overhead 2 24,000 Fixed manufacturing overhead, traceable 9* 108,000 Fixed manufacturing overhead, allocated 12 144,000 Total cost $ 43 $ 516,000 *One-third supervisory salaries; two-thirds depreciation of special equipment (no resale value). Requ