A mail-order house uses 15,750 boxes a year. Carrying costs are 60 cents per box a year and ordering costs are $96. The following price schedule applies.Number of BoxesPrice per Box1,000 to 1,999$1.252.000 to 4,9991.205,000 to 9,9991.1510.000 or more1.10a. Determine the optimal order quantity (Round your answer to the nearest whole number) Optimal order quantity = _______ boxes b. Determine the number of orders per year. (Round your answer to 2 decimal places.) Number of order _______ per yearA jewelry firm buys semiprecious...