Last month when Holiday Creations, Incorporated, sold 43,000 units, total sales were $172,000, total varlable expenses were $135,880, and fixed expenses were $37,400 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 sales volume by 400 units and total sales by $1,600 ? (Do not round intermediate calculations.)