Big Box Store has operated with a 30% average gross profit ratio for a number of years. It had $115,000 in sales during the second quarter of this year. If it began the quarter with $19,500 of inventory at cost and purchased $73,500 of inventory during the quarter, its estimated ending inventory by the gross profit method O O O $19,500 $12,500 $24,150 $34,500 $31,500