I am stuck with trying to find weighted average specifically cost of merchandise sold along with this question:

The beginning inventory at Funky Party Supplies and data on purchases and sales for a three-month period ending March 31, 2016, are as follows: Total Date Transaction Number of Units Per Unit Jan. 1 Inventory $60.00 $150,000 2,500 68.00 510,000 10 Purchase 7,500 28 Sale 3,750 120.00 450,000 30 Sale 120.00 150,000 1,250 Feb. 5 sale 120.00 60,000 500 10 Purchase 18,000 70.00 1,260,000 9,000 125.00 1,125,000 16 Sale 125.00 1,062,500 28 Sale 8,500 71.60 1,074,000 5 Purchase 15,000 Mar 125.00 1,250,000 10,000 14 Sale 25 Purchase 72.00 180,000 2,500 30 Sale 8,750 125.00 1,093,750