Ferris Company began January with 20,000 units of its principal product. The cost of each unit is $10. Merchandise transactions for the month of January are as follows:

Ferris Company began January with 20,000 units of its principal product. The cost of each unit is $10. Merchandise transactions for the month of January are as follows: "Includes purchase price and cost of freight 30,000 units were on hand at the end of the month. Required: Calculate January's ending inventory and cost of goods sold for the month using each of the following alternatives: 1. FIFO, periodic system 2. LIFO, periodic system 3. Average cost, periodic system