Last month when Holiday Creations, Incorporated, sold $40,000$ units, total sales were $$160,000,$ total variable expenses were $$120,000,$ and fixed expenses were $$35,800.$

Required:

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

$2.$ What is the estimated change in the company$$s net operating income if it can increase sales volume by $575$ units and total sales by $$2,300?($Do not round intermediate calculations.$)$