As an accountant for Lee Company, your supervisor gave you the following calculations of the gross profit for the first quarter:

Alternative Sales ($50 per unit) Cost of goods sold Gross Profit

A $500,000 $200,000 $300,000

B $500,000 228,000 272,000

C 500,000 213,333 286,667

The three alternative cost flow assumptions are FIFO, average, and LIFO (the alternatives are not necessarily presented in this sequence). Lee uses the periodic inventory system. The computation of the cost of goods sold under each alternative is based on the following:

Units Cost/Unit

Inventory, January 1 12,000 $20

Purchase, January 10 4,000 21

Purchase, February 15 6,000 22

Purchase, March 10 8,000 23

Required: Prepare schedules computing the ending inventory (in units and dollars) and proving the cost of goods sold shown here under each of the three alternatives.