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 Inventory 9 units at $41 $369 Aug. 13 Purchase 20 units at $43 860 Nov. 30 Purchase 10 units at $44 440 Available for sale 39 units $1,669 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) s c. Weighted average cost s