Required information Use the following information for the Quick Study below. Trey Monson starts a merchandising business on December 1 and enters into the following three inventory purchases. Also, on December 15, Monson sells 28 units for $45 each. Purchases on December 7 Purchases on December 14 Purchases on December 21 18 units @ $18.00 cost 32 units @ $27.00 cost 28 units @ $32.00 cost QS 6-10 Perpetual: Assigning costs with FIFO LO P1 Required: Monson uses a perpetual inventory system. Determine the costs assigned to the December 31 ending inventory based on the FIFO method.