Periodic Inventory Using FIFO, UFO, and Weighted Average Cost Methods The units of an item available for sale during the year were as follows: There are 9 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 (RIFO) 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 doliar)