Exercise 6-4 (Algo) Computing and Using the CM Ratio [LO6-3] Last month when Holiday Creations, Incorporated, sold 40,000 units, total sales were $160,000, total variable expenses were $115,200, and foxed expenses were $39,600 Required: 1. What is the company's contribution margin (CM) rato? 2. What is the estimated change in the company's net operating income if it can increase sales volume by 400 units and total sales by $1,600? (Do not round intermediate calculations.)