6. Periodic Inventory System and Inventory Costing Methods

In chronological order, the inventory, purchases, and sales of a single product for a recent month are as follows:

		Units	Amount per Unit
June 1	Beginning inventory	150	$30
4	Purchase	400	33
12	Purchase	800	36
16	Sale	1,300	60
24	Purchase	300	39

Using the periodic inventory system, compute the cost of ending inventory, cost of goods sold, and gross margin. Use the average-cost, FIFO, and LIFO inventory costing methods. Round unit costs to the nearest cent and round the final answers to the nearest dollar.

	Average-cost method	FIFO method	LIFO method
Ending inventory:	$	$	$
Cost of goods sold:	$	$	$
Gross margin:	$	$	$

Explain the differences in gross margin produced by the three methods.