The following is TJLS Corporation's contribution format income statement for last month:

Sales $1,200,000

Less: Variable Expenses: $800,000

Contribution Margin: $400,000

Less: Fixed Expenses: $300,000

Operating Income: $100,000

5. What is the company's margin of safety in dollars?

6. What is the company's degree of operating leverage? Explain how a company could use this number in terms a non-accountant could understand.

7. If the tax rate is 30%, how many units must be sold to attain an after-tax profit of $84,000?

You can use either the formula or equation methods to show your answers.