During its first year of operations, Maine Corporation made the following inventory purchases and sales.

Date	Units Purchased/(Sold)	Cost Per Unit	Inventory Balance (in units)
April 3	5,000	$4.25	5,000
April 10	2,000	$4.00	7,000
April 16	(4,000)		3,000
April 20	5,000	$4.50	8,000
April 25	2,000	$4.75	10,000

Calculate ending inventory and cost of goods sold using the 1) FIFO method under a periodic inventory system 2) FIFO method under a perpetual inventory system 3) LIFO method under a periodic inventory system and 4) LIFO method under a perpetual inventory system.