i just need to find out variable expenses. please explain how

[The following information applies to the questions displayed below] Raner, Harris and Chan is a consulting firm that specializes in information systems for medical and dental clinics. The firm has two offices - one in Chicago and one in Minneapolis. The firm classifies the direct costs of consulting jobs as variable costs. A contribution format segmented income statement for the company's most recent year is given: 3. Assume that sales in Chicago increase by $56.000 next year and that sales in Minneapolis remain unchanged. Assume no change in fixed costs