Last month when Holiday Creations, Incorporated, sold $40,000$ units, total sales were $$160,000,$ total variable expenses were $$121,600,$ and fixed expenses were $$36,900.$

Required:

$1.$ What is the company$$s contribution margin $($CM$)$ ratio?

$2.$ What is the estimated change in the company$$s net operating income if it can increase sales volume by $300$ units and total sales by $$1,200?$