Periodic Inventory by Three Methods The units of an item available for sale during the year were as follows: There are 4 units of the item in the physical inventory at December 31 . The periodic inventory system is used. a. Determine the inventory cost by the first in, first-out method. x b. Determine the inventory cost by the last-in, first-out method. s c. Determine the inventory cost by the weighted average cost method. Round average unit cost to the nearest cent and linal answers to the nearest whole dollar, if required. s Feedions a. Note that this exercise uses the periodic inventory system. Fifo means that the first units purchased ane assumed to be the first to be sold. Therefore, ending inventory costs for the period are calculated by taking the number of items remaining in the physical