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 6-13 Perpetual: Inventory costing with specific identification LO P1 Required: Monson sells 28 units for $45 each on December 15. Of the units sold, 14 are from the December 7 purchase and 14 are from the December 14 purchase. Monson uses a perpetual inventory system. Determine the costs assigned to the December 31 ending inventory when costs are assigned based on specific identification.