The predetermined manufacturing overhead rate is $12 per direct labor hour ($18.00+1.50). It was computed from a master manufacturing overhead badget based on normal production of 8,850 direct labor hours (5,900 units) for the month. Themaster budget showed total variable costs of $66,375 (\$7,50 per hour) and total fined overhead costs of $39,825 ( $4.50 per hour). Actual costs for October in producing 4,700 units were as follows. Tho purchwing degartment buys the quantities of rww materials that are expected to be uved in production cich menth. Raw The purchasing department buys the quantities of raw materials that are expected to be used in production each month. Raw materials inwentories, therefore, can be ignored. (a) Compute the total overhead variance, Total overhead variance $