$13$Margin of safetySales price per unit $$

$$

$$

$$

$$159$Variable cost per unit $$

$$

$$

$$ $$84$Total annual fixed manufacturing and operating costs $$

$$$$517,500$a$.$ Contribution margin per unit.CONTRIBUTION MARGIN $($

$)$ per unitb. $$Number of units that Ender must sell to break even.BREAK EVEN IN UNITS$($

$)$SALES IN UNITS $($

$)$