Blue Wave Company budgets the following unit sales for the next four months: September, $4,000$ units; October, $5,000$ units; November, $7,000$ units; and December, $7,600$ units. The company's policy is to maintain finished goods inventory equal to $60\%$ of the next month's unit sales. At the end of August, the company had $2,400$ finished units in inventory.

Prepare a production budget for each of the months of September, October, and November.