Problem 4 (15 marks) An aircraft manufacturer incurred the following costs last month (in thousands of dollars): A 270 B Airplane seats Depreciation on administrative offices Assembly workers' wages C 690 D Plant utilities 140 E Production supervisors' salaries 150 1,200 F Jet engines G Machine lubricants H Depreciation on forklifts I Property tax on corporate marketing office J Cost of warranty repairs K Factory janitors' wages 180 L Cost of designing new plant layout Machine operator's health insurance 60 M 3,155 Total Requirement (for Q1, 2, 3, 6, 7, you may list the letters corresponding to the cost items): If the cost object is an airplane, 1) Which of the above costs are direct materials? 2) Which of the above costs are direct labor? 3) Which of the above costs are manufacturing overhead? 4) Calculate the total inventoriable product costs. (Show steps for partial marks.) 5) Calculate the total period costs. (Show steps for partial marks.) 6) List three costs from the above that are fixed costs (i.e., costs that do not change with the # of aircrafts manufactured). List three costs from the above that are variable costs (i.e., costs that change in proportion to the # of aircrafts manufactured)