3) Stark Manufacturing Company had the following account balances for the 2021. Revenue Work-in-process inventory (January 1) Work-in-process inventory (December 31) Finished goods inventory (January 1) Finished goods inventory (December 31) Direct materials inventory (January 1) $3,000,000 140,400 171,000 540,000 510,000 10,000 Direct materials inventory (December 31) 32,000 Direct materials purchase 400,000 Indirect materials used 84,000 Direct manufacturing labor 480,000 Indirect manufacturing labor 186,000 Property taxes on manufacturing plant building 28,800 Salespersons' company vehicle costs 12,000 Depreciation of manufacturing equipment 264,000 Depreciation of office equipment 123,600 Miscellaneous plant overhead 135,000 92,400 305,400 Plant utilities General office expenses Marketing distribution costs Required: Calculate the following: a. Cost of direct materials used b- Cost of goods manufactured c- Cost of goods sold d- Gross margin f-Operating income 30,000