In September, Cullumber Industries sold $830$ units of product. The average sales price was $$40.$ During the month, fixed costs were $$7,704$ and variable costs were $70\%$ of sales.

$($a$)$

Determine the contribution margin in dollars, per unit, and as a ratio. $($Round Contribution margin to $0$ decimal places, e$.$g$.5,275.$

Other all answers to $2$ decimal places, e$.$g$.52\mathrm{.}75.)$