Periodic inventory using fifo, lifo, and weighted average cost methods the units of an item available for sale during the year were as follows: jan. 1 inventory 12 units at $5,400 $64,800 aug. 7 purchase 18 units at $6,000 108,000 dec. 11 purchase 15 units at $6,480 97,200 available for sale 45 units $270,000 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 $