Exercise $5-4($Algo$)$ Computing and Using the CM Ratio $[$LO$5-3]$

Last month when Holiday Creations, Incorporated, sold $38,000$ units, total sales were $$152,000,$ total variable expenses were $$117,040,$ and fixed expenses were $$35,900.$

Required:

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

$2.$ What is the estimated change in the company$$s net operating income if it can increase sales volume by $600$ units and total sales by $$2,400?($Do not round intermediate calculations.$)$