Question 2: Job-Order Costing: Calculating unit product costs Custom Corporation uses a job-order costing system with a single plantwide predetermined overhead rate based on machine-hours. The company based its predetermined overhead rate for the current year on the following data: Total machine-hours 10,000 Total fixed manufacturing overhead cost $71,000 Variable manufacturing overhead per machine-hour $ 2.50 Recently Job P512 was completed with the following characteristics: Number of units in the job 30 Total machine-hours 60 Direct materials $ 870 Direct labor cost $2,400 Required: a. Estimate the total manufacturing overhead cost. (3 marks) b. Calculate the predetermined overhead rate for the year. (2 marks) C. Calculate the amount of overhead applied to Job P512. (2 marks) d. Calculate the total job cost for Job P512 (3 marks) e. Calculate the unit product cost for Job P512 (2 marks). f. Why do most companies use predetermined overhead rates rather than actual overhead rates