Solve the following problems using Excel Annual demand for Integra Pencil Eraser at Office Supply.com is normally distributed with mean 1,000 and standard deviation 250. Office Supply.com purchases the erasers for 6 cents each and sells them for 20 cents each. There is a two-month lead time to deliver an order. The cost in employee time for performing the necessary paperwork to initiate and receive an order is $20, and a 22 percent annual interest rate is used in determining holding cost. The cost of a stock-out is the cost of lost profit tional 20 cents per eraser, which represents the cost of loss of goodwill. a. Find the optimal values of Q and R. b. Calculate the annual holding, ordering, and penalty costs of the policies determined in (a). C. What is the safety stock for this item at the optimal solution? d. Determine the Average time between orders. e. Determine the Proportion of orders with no stock-outs. f. Determine the Proportion of unmet demand. g. Determine the Proportion of demands satisfied as they occur