The information system department of a local university buys paper for its copier machine frequently. Andrea Webb, the office manager, would like to determine the best quantity to order each time and order is placed. She has estimated that the ordering cost is $12 each time an order is placed. The monthly demand for paper is 135 reams (500 sheets to a ream). The cost of paper is $6.50 per ream, and the carrying cost is 25 percent of the paper cost per month. How many reams should be ordered at a time, and what is expected average inventory level for copier paper?