Periodic Inventory Using FIFO, LIFO, and Weighted Average Cost Methods The units of an item available for sale during the year were as follows: There are 14 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. a. First-in, first-out (FIFO) method $ b. Last-in, first-out (LIFO) method $ c. Weighted average cost method $