589 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 15 units at $30 $450 Aug. 13 Purchase 19 units at $31 Nov. 30 Purchase 11 units at $32 352 Available for sale $1,391 There are 19 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 (FFO) method; (b) the last-in, first-out (LIFO) method; and () the welghted 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) 45 units Weighted average cost