In March, James Electronics had sales of $2,540,000 ( 25,400 units), total variable expenses of $1,524,000, and total fixed expenses $820,000. Required: 1. What is the company's CM ratio? 2. Using the CM ratio, calculate the break-even level of sales in dollars. 3. What is the break-even level of sales in units? 4. Estimate the change in the company's operating income if it increased its total sales by $620,000