Periodic imventory using FIFO, LIFO, and weighted average cost methods The units of an item available for sale during the year were as follows: There are 75 units of the item in the physicat inventory at December 31. The penodic invantory system is used, Determine the inventory cost uating the (a) first-in, fintout (FIFO) method; (b) last-in, first-out (UFO) method; and (c) weighted average cost method