Required information Trey Monson starts a merchandising business on December 1 and enters into the following three inventory purchases. Also, on December 15, Monson sells 25 units for $45 each. Purchases on December 7 Purchases on December 14. Purchases on December 21 15 units 29 units 25 units $18.00 cost $27.00 cost $32.00 cost Required: Monson uses a perpetual Inventory system. Determine the costs assigned to the December 31 ending inventory based on the FIFO method.