The units of an item available for sale during the year were as follows:

Jan. 1 Inventory 18 units at $1,440

Feb. 17 Purchase 36 units at $1,656

July 21 Purchase 42 units at $1,872

Nov. 23 Purchase 24 units at $1,980

There are 32 units of the item in the physical inventory at December 31. The periodic

inventory system is used. Determine the inventory cost by (a) the first-in, first-out method,

(b) the last-in, first-out method, and (c) the weighted average cost method.