A company purchased 100 units for $20 each on January 3 t purchased 300 units for $20 on February 28. It sold a total of 350 units for $100 each from March 1 through December 31. If the company uses the last-in, first-out inventory costing method, calculate the amount of ending inventory on December 31. (Assume that the company uses a perpetual inventory system.) $4,000 $1,000 $7,000 $7, 650