Final answer:
The required average inventory level at the new central Memphis warehouse, required to maintain the system's present 98%, would be approximately 16,370 units.
Step-by-step explanation:
The square root rule is used to determine the required average inventory level when combining multiple warehouses into a central one. According to the rule, the required average inventory level at the new central Memphis warehouse can be found by taking the square root of the sum of the squares of the average inventory levels of the individual warehouses.
In this case, the sum of the squares of the average inventory levels of the four warehouses is (8000^2) + (10,000^2) + (10,000^2) + (8000^2) = 268,000,000.
Taking the square root of this sum gives us approximately 16,370. Therefore, the required average inventory level at the new central Memphis warehouse, required to maintain the system's present 98%, would be approximately 16,370 units.