Current Attempt in Progress REI sells snowboards. Assume the following information relates to REI's purchases of snowboards during September. During the same month, 106 snowboards were sold. REI uses a periodic inventory system. Date Explanation Units Unit Cost Total Cost Sept. 1 Inventory 15 $105 $1,575 Sept. 12 Purchases 47 108 5,076 Sept. 19 Purchases 52 109 5,668 Sept. 26 Purchases 22 110 2,420 Totals 136 $14,739