Helen's Boards sells a snowboard, Xpert, that is popular with snowboard enthusiasts. Information relating to Helen's purchases of Xpert snowboards during September is shown below. During the same month, 125 Xpert snowboards were sold. Helen's uses a periodic inventory system. Date Explanation Units Unit Cost Total Cost Sept. 1 Inventory 28 $97 $2,716 Sept. 12 Purchases 45 104 4,680 Sept. 19 Purchases 20 106 2,120 Sept. 26 Purchases 50 107 5,350 Totals 143 $14,866