surf Company can sell all of the two surfboard models it produces, but it has only 472 direct labor hours available. The Glide model requires 2 direct labor hours per unit. The Ultra model requires 4 direct labor hours per unit. The contribution margin per unit is $272 for Glide and $444 for Ultra. (a) Compute the contribution margin per direct labor hour for each product. (b) Determine the best sales mix and the resulting contribution margin