Rosemary is planning to make fancy multi$-$tiered wedding cakes for the next wedding season. To make the cakes, she must invest $$834$ in some special baking pans and tools. To get started, she needs to spend $$1800$ to advertise in the newspaper. She estimates that supplies and materials for each cake will cost $$60.$ She is planning to set the price for each cake at $$499.$

perform a break$-$even analysis showing computation of the:

$($a $)$ Contribution Margin;

$($b$)$ Contribution Rate;

$($c$)$ Break$-$even point in units;

$($d$)$ Break$-$even point in sales dollars.