Consider a small landscaping company run by Mr. Viemeister. He is considering increasing his firm’s capacity. If he adds one more worker, the firm’s total monthly revenue will increase from $50,000 to $58,000. If he adds one more tractor, monthly revenue will increase from $50,000 to $62,000. Each additional worker costs $4,000 per month, while an additional tractor would also cost $4,000 per month.