help on practice problem?

Miller Company's contribution format income statement for the most recent month is shown below: Required: (Consider each case independently): 1. What is the revised net operating income if unit sales increase by 19% ? 2. What is the revised net operating income if the selling price decreases by $1.50 per unit and the number of units sold increases by 1998 ? 3. What is the revised net operating income if the seling price increases by $1,50 per unit, fixed expenses increase by $8,000, and the number of units sold decreases by 6% ? 4. What is the revised net operating income if the selling price per unit increases by 20%, variable expenses increase by 20 cents per unit, and the number of units sold decreases by 13%