Final answer:
The average inventory using the EOQ model is approximately 952 units.
Step-by-step explanation:
To calculate the average inventory using the Economic Order Quantity (EOQ) model, you can use the formula:
Average Inventory = √(2 * Annual Demand * Ordering Cost / Annual Holding Cost)
Substituting the given values, we get: Average Inventory = √(2 * 11000 * 160 / 21) ≈ 952
Therefore, the average inventory is approximately 952 units.