The following is Silver 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:

$1.$ What is the company's contribution margin ratio?

$2.$ What is the company's break$-$even in units?

$3.$ If sales increase by $100$ units, by how much should operating income increase?

$4.$ How many units would the company have to sell to attain target operating income of $$225,000?$

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

$6.$ What is the company's degree of operating leverage?