Cullumber Company Inc. had a beginning inventory of 110 units of Product RST at a cost of $9 per unit. During the year, purchases were: Feb. 20 630 units at $10 Aug. 12 450 units at $12 May 5 500 units at $11 Dec. 8 110 units at $13 Cullumber Company uses a periodic inventory system. Sales totaled 1,540 units. (a) Determine the cost of goods available for sale. The cost of goods available for sale $ Calculate weighted-average cost per unit. (Round answer to 3 decimal places, e.g. 5.125.) Weighted-average cost per unit