Windy Company uses a periodic inventory system. On December 31, 2016, Windy counts its inventory and determines that it has $77,000 of inventory on hand. On December 31, 2015, inventory was $107,500. Windy made inventory purchases totaling $77,000 during the year. What is Windy's cost of goods sold in 2016? Enter the formula and calculate Windy's cost of goods sold in 2016