To more efficiently manage its inventory, Treynor Corporation maintains its internal inventory records using first-in, first-out (FIFO) under a perpetual inventory system. The following information relates to its merchandise inventory during the year:

Jan. 1 ...........Inventory on hand—20,000 units; cost $12.20 each.
Feb. 12 .......Purchased 70,000 units for $12.50 each.
Apr. 30 .......Sold 50,000 units for $20.00 each.
Jul. 22 .........Purchased 50,000 units for $12.80 each.
Sep. 9 .........Sold 70,000 units for $20.00 each.
Nov. 17 .......Purchased 40,000 units for $13.20 each.
Dec. 31 .......Inventory on hand—60,000 units.

Required:
1. Determine the amount Treynor would calculate internally for ending inventory and cost of goods sold using first-in, first-out (FIFO) under a perpetual inventory system.
2. Determine the amount Treynor would report externally for ending inventory and cost of goods sold using last-in, first-out (LIFO) under a periodic inventory system.
3. Determine the amount Treynor would report for its LIFO reserve at the end of the year.
4. Record the year-end adjusting entry for the LIFO reserve, assuming the balance at the beginning of the year was $10,000.