Final answer:
The weeks of supply held in inventory is 13 weeks.
Step-by-step explanation:
To calculate the weeks of supply held in inventory, we need to use the formula:
Weeks of Supply = 52 / Inventory Turnover.
Inventory turnover is the ratio of cost of goods sold to average inventory.
In this case, the cost of goods sold is $12 million and the average inventory is $3 million, so the inventory turnover is 4.
Hence, the weeks of supply held in inventory is 52 / 4 = 13 weeks.