Final answer:
The net profit margin is calculated by dividing the net income by total sales and then multiplying by 100, resulting in a net profit margin of 12%. The correct answer is option 4.
Step-by-step explanation:
To calculate the net profit margin, we need to divide the net income by the total sales and then multiply by 100 to convert it to a percentage.
Using the provided figures, we divide $78,000 (net income) by $650,000 (sales), resulting in approximately 0.12.
To get the percentage, we multiply by 100, giving us a net profit margin of 12%.