I solve this question by get the overhead of each department and add it together but i see many people solve it by add the total estimate overhead together and divide it and get the different total rate ( i get the rate for each department seperately) Can you explain which one is correct and why?

The following information applies to the questions displayed below.) Sweeten Company had no jobs in progress at the beginning of March and no beginning inventories. The company has two manufacturing departments-Molding and Fabrication. It started, completed, and sold only two jobs during March- Job P and Job Q. The following additional information is available for the company as a whole and for Jobs P and Q (all data and questions relate to the month of March): Estimated total machine-hours used Estimated total fixed manufacturing overhead Estimated variable manufacturing overhead per machine-hour Molding Fabrication 2,500 1,500 $12, 250 $16, 350 $ 2.30 $ 3.10 Total 4,000 $28,600 Job P $22.000 $28, 200 Job O 0. $12.500 $11, 100 Direct materials Direct labor cost Actual machine-hours used: Holding Fabrication Total 2,600 1.500 4.100 1,700 1,800 3.500 Sweeten Company had no underapplied or overapplied manufacturing overhead costs during the month. Required: For questions 1-9, assume that Sweeten Company uses departmental predetermined overhead rates with machine-hours as the allocation base in both departments and Job P included 20 units and Job Q included 30 units. For questions 10-15, assume that the company uses a plantwide predetermined overhead rate with machine-hours as the allocation base. What was the total manufacturing cost assigned to Job P? (Do not round Intermediate calculations.)