Periodic Inventory by Three Methods The units of an item avaliable for sale during the year were as follows: There are 14 units of the liem in the physlcal inventory at December 31. The periodic inventory system is used. Round average unit cost to the nearest cent and fina answers to the nearest whole doliar, if required. a. Determine the inventory cost by the first-in, first-out method. b. Determine the inventory cost by the last-in, first-out method. c. Determine the inventory cost by the weighted average cost method