AAA Co. uses a periodic inventory system and has the following information in regard to its inventory: Beginning inventory Purchase on January 25 Purchase on March 15 Purchase on October 2 Goods available for sale 200 units 15 300 units@ 16 200 units @ 17 400 units @ 18 $ 3,000 4,800 3,400 7,200 $18,400 There are 500 units in ending inventory. What is the amount of the ending inventory using the LIFO method? $3,000 $7,200 $7,800 $8,900