Gladstone Limited tracks the number of units purchased and sold throughout each accounting period but applies its inventory costing method at the end of each period, as if it uses a periodic inventory system. Assume its accounting records provided the following information at the end of the annual accounting period, December 31.

Transactions Beginning inventory, January 1 Transactions during the year: a. Purchase, January 30 b. Sale, March 14 ($10 each) a. Purchase, May 1 d. Sale, August 31 ($10 each) Units 1,900 2,500 (1,500) 1,200 (1,900) Unit Cost $ 4.00 6.00 8.00 Goods available for Ending Cost of goods sale inventory sold a . Weighted average cost . b . \\First - in , first - out . C . Specific identification