Alta Ski Company's inventory records contained the following information regarding its latest ski model. The company uses a periodic inventory system 800 units $90 each Beginning inventory, January , 2018 Purchases: January 15 January 21 1,700 units $105 each 1,500 units $110 each Sales: January 5 January 22 January 29 750 units$130 each 1,150 units $140 each 600 units $145 each nding inventory, January 31, 2018 1,500 units