company had the following purchases and sales during its first year of operations: purchases sales january: 11 units at $125 7 units february: 21 units at $130 4 units may: 16 units at $135 8 units september: 13 units at $140 7 units november: 11 units at $145 15 units on december 31, there were 31 units remaining in ending inventory. using the perpetual lifo inventory valuation method, what is the cost of the ending inventory? (assume all sales were made on the last day of the month.)