Johansson Company developed the following static budget at the beginning of the company's accounting period: Revenue (8,000 units): $16,000; Variable costs: $4,000; Contribution margin: $12,000; Fixed costs: $4,000; Net income: $8,000; If actual production totals 8,200 units, the flexible budget would show variable costs of $4,100. How do you get this answer ($4,100)?