TB MC Qu. 9-176 Dubberly Corporation's cost formula for its manufacturing Dubberly Corporabtion's cost formula for ins manufacturing overhead is $30,600 per month plus $64 per machine-hout For the month of March, the company planned for activity or 7,900 machine hours, but the actual level of activity was 7,880 machine-hours. The actual monufacturing overhead for the month was $558,610. The spending variance for manufacturing overhead in March would be closest to: Muhiple Choice 523,690F 522.410u 523690U $22.410F