( Cases 1. A 10% increase in contribution margin, holding revenues constant 2. A 10% decrease in contribution 3. A3\% increase in fixed costs 5. An 8% increase in units sold 6. An 8% decrease in units sold 7. A 10% increase in fixed costs and a 10% increase in units sold 8. A 3% increase in fixed costs and a 3% decrease in variable costs 9. Which of these alternatives yields the income? Explain why this is the case