Time left 1:22:41 of Midwest Office Products uses the retail method to estimate ending inventory in its monthly financial statements. The following information is available for the month ended May 31: Cost Retail Sales $ 300,000 Inventory, May 1 $ 137,400 $ 198,000 Net purchases $184,800 $ 273,000 Goods available for sale $ 322,200 $ 471,000 Determine the cost ratio that should be used in estimating the May 31 inventory using the retail method (Round your final answer percentage to one decimal point) Select one a 63.8% b. 69.4% c. 66.0% d. 68.4%