Flint Corp. makes and sells deck coating which is sold by the gallon. Two pounds of sand are needed to make one gallon of deck coating. Budgeted production of deck coating for the next two months follows: September 21,700 gallons October 34,200 gallons The company wants to maintain monthly ending inventories of sand equal to 20% of the following month's production needs. On August 31, 8,680 pounds of sand were on hand. How much sand should be purchased in September? Sand to be purchased