Final answer:
Method 2 is the best production method, but if the cost of labor rises, Method 3 would be the best production method.
Step-by-step explanation:
In order to determine the best production method, we need to calculate the cost of each method.
Method 1 requires 50 units of labor at $100/unit and 10 units of capital at $400/unit, resulting in a total cost of $9500.
Method 2 requires 20 units of labor at $100/unit and 40 units of capital at $400/unit, resulting in a total cost of $9000.
Method 3 requires 10 units of labor at $100/unit and 70 units of capital at $400/unit, resulting in a total cost of $11,000.
Therefore, Method 2 is the best production method.
If the cost of labor rises to $200/unit, the cost of Method 1 would be $15,000, the cost of Method 2 would be $14,000, and the cost of Method 3 would be $13,000.
Therefore, if the cost of labor rises, Method 3 would be the best production method.