Can you please help me calculate part B

Carla Vista Co. sells a snowboard, EZslide, that is popular with snowboard enthusiasts. Below is information relating to Carla Vista Co's purchases of EZslide snowboards during September. During the same month, 116 EZslide snowboards were sold. Date Explanation Units Unit Cost Total Cost Sept. 1 Inventory 15 $100 $1,500 Sept. 12 Purchases 49 103 5,047 Sept. 19 Purchases 58 104 6,032 Sept. 26 Purchases 23 105 2,415 Totals 145 $14,994 Additional data regarding the company's sales of EZslide snowboards are provided below. Assume that Carla Vista Co. uses a perpetual inventory system. Date Units Sept. 5 Sale 8 Sept. 16 Sale 54 Sept. 29 Sale 54 Totals 116\fCalculate the average unit cost. (Round answers to 3 decimal places, e.g. 5.125.) September 1 tA 100.000 September 5 $ 100.000 September 12 $ 102.625 September 16 tA 102.625 September 19 103.954 September 26 $ 104.244 September 29 tA 104.244