Zaccaria Corporation has provided the following contribution format income statement. All questions concern situations that are within the relevant range. Sales (5,000 units) Variable expenses Contribution margin Fixed expenses Net operating income Required: a. What is the contribution margin ratio? $ 300,000 240,000 60,000 58,800 $ 1,200 b. If sales increase to 5,040 units, what would be the estimated increase in net operating income? c. If the selling price increases by $4 per unit and the sales volume decreases by 400 units, what would be the estimated net operating income? d. What is the break-even point in unit sales? e. What is the margin of safety in dollars? f. What is the degree of operating leverage?