During July 2007 a Company sold 500 units of products for $8,000. The following data is available:

Units Cost

Beginning Inventory 200 $2

Purchase 1 80 4

Purchase 2 120 6

Purchase 3 300 9

Purchase 4 180 12

A sale of 500 units was made after Purchase 3

Determine:

1. Cost of goods available for sale and ending inventory in units.

2. the costs that should be assigned to cost of goods sold and ending inventory under the Perpetual Inventory System;

Use: the average-cost; FIFO inventory costing method; LIFO inventory costing method

Show: the gross margin for each alternative