Question 3 of 41 < > The following costs were incurred by a manufacturing company: Materials used in product Depreciation on plant $120,800 6,300 Property taxes on plant 900 Labour costs of assembly-line workers 150,400 Factory supplies used 2,550 Advertising expense 4,650 Factory insurance 21,550 Factory supervisor's salary 50,700 -13 E! Work in process inventory was $5,000 at January 1 and $6,700 at December 31. Finished goods inventory was $30,100 at January 1 and $29,700 at December 31.