Kelsh Company uses a predetermined overhead rate based on machine-hours to apply manufacturing overhead to jobs. The company has provided the following estimated costs for next year. Direct materials ..... $10,000 Direct labor ..... $30,000 Sales commissions ..... $40,000 Salary of production supervisor ..... $20,000 Indirect materials ..... $4,000 Advertising expense ..... $8,000 Rent on factory equipment ..... $10,000 Kelsh estimates that 5,000 direct labor-hours and 10,000 machine-hours will be worked during the year. What is the predetermined overhead rate per hour?