Trey Monson starts a merchandising business on December 1 and enters into the following three irveritory purchases Monson uses a perpetual imventory system. Aso, on December 15, Monson sells 15 units for $29 each Durchaves on Deceaber-7 Purchases on Decenber 14 Purchases on Decesber 21 16unitse$15.69cost20unitse$21.69cost15units523.69cost QS 5-11 (Algo) Perpetual: Assigning costs with FIFO LO P1 Required: Determine the costs assigned to the December 31 ending inventory based on the fifo method