please some one help me to this question

Priya, a small business owner who sells only one product, started March with no inventory. Over the course of the month, she made the following purchases: Date Number of units purchased Total cost of order March 1 10 $920 March 10 5 $480 March 18 8 $760 March 25 10 $930 March 30 3 $300 Here is Priya's sales data: Date March 4 March 7 March 8 March 11 March 16 March 20 March 24 March 27 March 31 Number of units sold 2 4 1 3 2 S 4 6 4 Total sales value $300 $520 $170 $440 $290 $600 $510 $620 $520 a) Assuming Priya uses the first-in-first-out inventory costing method, what is her gross margin? b) Assuming Priya uses the moving-weighted-average inventory costing method, what is the value of her ending inventory