Last period Hartig Corporation sold 40,000 units, total sales were $315,000, total variable expenses were $255,150, and fixed expenses were $38,600. Required: 1. What is the company's contribution margin (CM) ratio? 2. What is the estimated change in the company's net operating income if it can increase total sales by $2,400? (Do not round intermediate calculations.) 1. Contribution margin ratio 2. Estimated change in net operating income-