Buckner Company started business on January 1, 2016 It has the following inventory activity during the year 2016: January 1 Purchase 2,000 units @ $10.00 June 2 Purchase 4,000 units @ $11.00 October 3 Purchase 2,500 Units @ $11.50 The ending inventory on December 31, 2016 is 2,800 units. The value of the ending inventory under LIFO is?

I know that the answer to the problem is 28,800 but I need steps to understand the concept.