Buyers Products Company distributes an item known as a tie bar, which is a U-bolt used on truck equipment. The following data have been collected for this item: Monthly demand forecast d is 11107, standard deviation is 3099, replenishment lead time is 1.5 months, item value C is $0.11 per unit, setup cost is $10 per order, carrying cost is 20% of its value per year, in-stock probability during lead time is set at 75%. What is the average inventory level for this problem?