Colt Company produces two skateboard models. Machine time per unit for Hero is two hours and for Flip is one hour. The machine's

capacity is $1,620$ hours per year. Colt can sell up to $512$ units of Hero and $896$ units of Flip per year. Selling prices and variable costs

follow.

selling price for hero is $156$ and for flip its $98$ variable cost for herpo is $52$ and for flip its $56$

$($a$)$ Compute the contribution margin per machine hour for each product.

$($b$)$ Determine the best sales mix of products.