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

Sales $$1,400,000$

Less: variable expenses $800,000$

Contribution margin $600,000$

Less: fixed expenses $400,000$

Operating income $$200,000$

The company has no beginning or ending inventories and produced and sold $20,000$ units during the month.

Required:

a$)$ What is the company's contribution margin ratio?

b$)$ What is the company's break$-$even in units?

c$)$ If sales increase by $100$ units, by how much should operating income increase?

d$)$ How many units would the company have to sell to attain target operating income of $$225,000?$

e$)$ What is the company's margin of safety in dollars?

f$)$ What is the company's degree of operating leverage?