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 28 units for $10 each. Purchases on December 7 Purchases on December 14 Purchases on December 21 18 units $4.00 cost 35 units $6.00 cost 28 units $7.00 cost Required: Monson uses a perpetual inventory system. Determine the costs assigned to the December 31 ending inventory based on the FIFO method. Perpetual FIFO Goods Purchased Cost Per Goods Unit Purchased of Units Cost of Goods Sold #of Units Cost Per Cost of Goods Sold Unit Sold Date Inventory Balance Cost Per # of Units Inventory Unit Balance December 7 December 14 December 15 December 121