If I have a sales and inventory records for January through March 2006
were as follows:
       	                                        Sets 	UnitCost     TtlCost 
Beginning inventory, Jan. 1 . . . . . . . . . 	460	$30 	     $13,800 
Purchase, Jan. 16 . . . . . . . . . . . .  . . 	110	32	      3,520
Sale, Jan. 25 ($45 per set) . . . . . . . .. . 	216	 	
Purchase, Feb. 16 . . . . . . . . . . . . .. . 	105	36	      3,780
Sale, Feb. 27 ($40 per set) . . . . . . . .  . 	307	 	
Purchase, March 10 . . . . . . . . . . . . . . 	150	28	      4,200
Sale, March 30 ($50 per set) . . . . . . . .. 	190	 	

What I need to calculate:
1. What are the amounts for ending inventory, cost of goods sold, and
gross margin under the following costing alternatives using the
periodic inventory method which means that all sales are assumed to
occur at the end of the period no matter when they actually occurred.

a. FIFO
b. LIFO
c. Average cost
2. Which alternative results in the highest gross margin? Why?