P18.34 Basic CVP relationships; income taxes: manufacturer LO18.7 Refer to the data given in Problem 18.33. Now assume that Vine pays income taxes of 30 per cent. Required: 1. What is Vine's break-even point in units? 2. What is the company's break-even point in sales dollars? 3. How many units would Vine have to sell in order to earn a profit of $600 000 after tax? 4. What is the firm's safety margin? 5. If Vine's direct labour costs increase by 10 per cent, what selling price per unit must it charge to maintain the same contribution margin ratio