Periodic Inventory by Three Methods The units of an item available for sale during the year were as follows: Jan. 1 Inventory 12 units at $35 Feb. 17 Purchase 17 units at $37 Jul 21 Purchase 15 units at $38 Nov. 23 Purchase 9 units at $38 There are 11 units of the item in the physical inventory at December 31. The periodic inventory dollar, required a. Determine the inventory cost by the first in, first-out method b. Determine the inventory cost by the last in, first-out method c. Determine the inventory cost by the weighted average cost