Periodic inventory using FIFO, LFF, and welohted average cost methods The units of an item avalable for sale during the vear were as follows: There are 19 units of the item in the phivical irventory at December 31 . The periodic inventory system is used. Determine the inventory cost using the (a) first-in, firstout (FIFO) methoo; (b) last-in, first-out (LIFO) method; and (c) weighted average cost method (round per-unit cost to two decimal places and vour final answer to the nearest whole dollar). a. When the firo method is used, costs are included in cost of goods sold in the order in which they were purchased. b. When the Lifo method is used, the cont of the units sold is the cost of the most recent purchaves: c. The average cost methoo is sometimes calied the weighted average method. The average cost method ises the overage unit cost for determining cost of goods sold and the ending inventory