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 muffier. Use the information in the following table to answer the below questions. a. What is the optimal target level (order-up-to level)? Note: Use Excel's NORM.S.INV() function to find the z value. Round z value to 2 decimal places and final answer to the nearest whole number