Iron Decor manufactures decorative iron railings. In preparing for next year's operations, management has developed the following estimates: Required: Compute the following items: Unit contribution margin. Contribution margin ratio. Break-even in dollar sales. Margin of safety percentage. If the sales volume increases by 20% with no change in total fixed expenses, what will be the change in net operating income? If the per unit variable production costs increase by 15%: and if fixed selling and administrative expenses increase by 12%, what will be the new break-even point in dollar sales