Problem 20-36 (Algo) Palin's Muffler Shop has one standard muffler that ts a large variety of cars. The shop wishes to establish a periodic review system to manage inventory ofthis standard muffler. Use the information in the following table to determine the optimal inventory target level (or order-up-to level). Annual demand 2,200 Standard deviation of daily demand 6 Item cost $38.00 Annual holding cost 23 Review period 18 mufflers mufflers per working day per muffler % of item value working days Ordering cost $ 55 per order Service probability 88 % Lead time 5 working days Working days 275 per year a. What is the optimal target level (order-up-to level)? (Use Excel's NORMSINVO function to find the correct critical value for the given aIevel. Do not round intermediate calculations. Round "2" value to 2 decimal places and final answer to the nearest whole number.) 2\" b. If the service probability requirement is 91 percent, the optimal target level will: 0 Increase O Decrease 0 Stay the same