Adams Corporation uses a periodic inventory system and the retail inventory method to estimate ending inventory and cost of goods sold. The following data are available for the month of September 2021 Beginning inventory Net purchases Net markups Net markdowns Net sales Cost Retail $21,000 $35,000 10,500 2 4,000 11,000 2 The company used the average cost flow method and estimated Inventory at the end of September to be $17,437.50. If the company had used the LIFO cost flow method, the cost-to-retail percentage would have been 50%. Required: Compute net purchases at retail and net sales for the month of September using the information provided. (Do not round your intermediate calculations.) Net purchases at retail 18,000 Net sales