Exercise $6-4($Algo$)$ Computing and Using the CM Ratio $[$LO$6-3]$

Last month when Holiday Creations, Incorporated, sold $36,000$ units, total sales were $$144,000,$ total variable expenses were $$116,640,$

and fixed expenses were $$36,800.$

Required:

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

What is the estimated change in the company's net operating income if it can increase sales volume by $625$ units and total sales by

$$2,500?($Do not round intermediate calculations.$)$