how to calculate -cost of goods sold -gross margin -ending inventory

using the weighted average

Saddlery Company sells leather saddles and equipment for horse enthusiasts. Sac following schedule relates to the company's inventory for the month of May: Cost Sales May 1 Beginning inventory 210 units $126,000 5 Sale 140 units $109,200 9 Purchase 70 units $46,200 13 Purchase 280 units $201.600 24 Sale 280 units $285,200 27 Sale 70 units $67,200 30 Purchase 105 units $83.160