Carlson uses the periodic inventory system. For the current month, the beginning inventory consisted of 7,200 units that cost $12 each. During the month, the company made two purchases: 3,000 units at $13 each and 12,000 units at $13.50 each. Checkers also sold 12,900 units during the month. Using the FIFO method, what is the ending inventory? a. $120,438. b. $111,600. c. $125,550. d. $113,700.

Could I have a full explanation on how to do this?