problem: $2-23$cvp applications; contribution margin ratio degree of operation leverage Lo$2-1$lo$2-3$lo$2-4$lo distributes a high$-$quality wooden birdhouse that sells for $$20$per unit. variable expenses are $$8$per unit, and fixed expenses total $$180,000$per year. its operating results for last year were as follows:

sales $$400,000$

variable expenses $160,000$

contribution margin $240,000$

fixed expenses $180,000$

net operating income $60,000$

what is the products CM ratio?