Please check my work:

Given:

Aranas Manufacturing, a tool retailer, began year 20x7 with 21,500 units of product in its January 1 inventory, at a cost of $12.50 for each unit. It made successive purchases of its product in year 20x7, as follows. The company uses a periodic inventory system. On December 31, 20x7, a physical count reveals that 35,000 units of its product remain in inventory.