Reamer corporation uses a predetermined overhead rate based on machine-hours to apply manufacturing overhead to jobs. the corporation has provided the following estimated costs for next year: direct materials $ 1,000 direct labor $ 3,000 sales commissions $ 4,000 salary of production supervisor $ 2,000 indirect materials $ 400 advertising expense $ 800 rent on factory equipment $ 1,000 reamer estimates that 500 direct labor-hours and 1,000 machine-hours will be worked during the year. the predetermined overhead rate per hour will be:.