The Sattler Corporation has provided the following contribution margin format income statement. All questions concern situations that are within the relevant range. Sales (8,000 units) Variable Costs Contribution Margin Fixed Costs Net Operating Income $ 480,000 336,000 $ 144,000 142,200 $ 1,800 Required: 1. What is the contribution margin per unit? 2. What is the contribution and variable expense ratio? 3. If sales decline to 7,900 units, what would be the estimated net operating income? 4. If the variable cost per unit increases by $5, spending on advertising increases by $2,000, and unit sales increase by 3,400 units, what would be the estimated net operating income? 5. Based upon the original data, what is the break-even point in unit sales and sales dollars? 6. Based upon the original data, estimate how many units must be sold to achieve a target profit of $50,400. 7. Based upon the original data, what is the margin of safety percentage? 8. Based upon the original data, using the degree of operating leverage, what is the estimated percent increase in net operating income of a 15% increase in sales