Palin's Muffler Shop has one standard muffler that fits a large variety of cars, The shop wishes to establish a periodic review system to manage inventory of this standard muffer. Use the information in the following table to determine the optimal inventory target level (or order-up-to level). a. What is the optimal target level (order-up-to level)? (Use Excel's NORMSINV) function to find the correct critical value for the given a-level. Do not round intermediate calculations. Round " z value to 2 decimal places and final answer to the nearest whole number.) b. If the service probability requirement is 97 percent, the optimal target level will: Increase Decrease Stay the same