Trey Monson owns a merchandising business and purchased inventory on three occasions in December: 10 units for $19 each on December 7, 20 units for $25 each on December 14, and 15 units for $27 each on December 21. On December 15, Monson sold 15 units for $33 each. Using the LIFO method, the costs assigned to ending inventory would be the costs of the units from the most recent purchase on December 21.