for 2010, omaha mechanical has a monthly overhead cost formula of $42,900 + $6 per direct labor hour. The firm's 2010 expected annual capacity is 78,000 direct labor hours, to be incurred evenly each month. Making one hit of the company's product requires 1.5 direct labor hours. the Overhead per unit of product is $4.37 per unit b) prepare journal entries to record the application of overhead to work in process inventory and the incurrence of $128,550 of actual overhead in january 2010, when 6,390 direct hours were worked