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 6 units at $35 $210 Aug. 13 Purchase 19 units at $36 684 Nov. 30 Purchase 18 units at $38 684 Available for sale 43 units $1,578 There are 13 units of the item in the physical inventory at December 31. The periodic inventory system is used. Determine the inventory cost using the (a) first-in, first-out (FIFO) method; (b) last-in, first-out (LIFO)