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 2013:

Cost Retail
Beginning inventory $ 21,000 $ 35,000
Net purchases 10,500 ?
Net markups 4,000
Net markdowns 1,000
Net sales ?

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.