3. Parasol Systems sells motherboards for personal computers. For quantities up through 25 , the firm charges $350 per board; for quantities between 26 and 50, it charges $315 for each board purchased beyond 25; and it charges $285 each for additional quantities over 50. A large communications firm expects to require these motherboards for the next ten years at a rate of at least 140 per year. Order setup costs are $30 and holding cost is based on an 18 percent of annual interest rate. What would be the size of the standing order