I do not know how to arrive at the answer

Question

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	4	units at $29	$116
July 7	Purchase	18	units at $32	576
Nov. 23	Purchase	20	units at $33	660
42	units	$1,352

There are 21 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 (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)	$
c.	Weighted average cost	$

Answer 1

The inventory cost is as follows: FIFO a) 4 units at $29 = $116 plus 17 units at $32.= $544 for a total inventory cost of $660, LIFO b) 20 units at $33= $660 plus 1 unit at $32= $32 for a total inventory cost of $692. Weighted average cost c.) get the weighted average per unit, Total cost at $1,352/42 = $32.19 per unit. This can then be multiplied by the 21 units of inventory cost . The total inventory cost is $676.