eBook Show Me How Periodic Inventory Using FIFO, LIFO, and Weighted Average Cost Method. The units of an item available for sale during the year were as follows: Jan. 1 Aug. 13 Inventory Purchase 13 units at $40 $520 19 units at $42 798 Nov. 30 Purchase 14 units at $43 602 Available for sale 46 units $1,920 There are 18 units of the item in the physical inventory at December 31. The periodic inventory system is used. Determine the inventory cost using (a) the first-in, first- out (FIFO) method; (b) the last-in, first-out (LIFO) method; and (c) the weighted average cost method (round per-unit cost to two decimal places and your final answer to the nearest whole dollar). a. First-in, first-out (FIFO) b. Last-in, first-out (LIFO) c. Weighted average cost