4 The computation of equivalent units under the FIFO method: treats units in the beginning work in process inventory as if they were started and completed during the current period. treats units in the beginning work in process inventory as if they represent a separate batch of goods separate and distinct from goods started and completed during the current period. treats units in the ending work in process inventory as if they were started and completed during the current period. ignores units in the beginning and ending work in process inventories. 5 Raider Manufacturing uses the weighted average method in its process costing system The Moulding Department is the second department in its production process. The data below summarize the department's operations in January Un Per cent Complete Beginning work in process inventory 7,700 10% Transferred in from the prior department during January 64,000 Completed and transferred during January 63,800 Ending work in process inventory 7,900 80%