Answer:
$22.86
Explanation:
                          Model A12   Model B22  Model C124
Selling price per unit             $53         $101       $406
Variable costs per unit           $45         $81        $315
Contribution margin per unit      $8           $20       $91
Weighted-Average Unit Contribution Margin = (Model A12 Contribution margin per unit * Sales mix) + (Model B22 Contribution margin per unit * Sales mix) + (Model C124 Contribution margin per unit * Sales mix)
Weighted-Average Unit Contribution Margin = ($8 * 59%) + ($20 * 27%) + ($91 * 14%)\
Weighted-Average Unit Contribution Margin = $4.72 + $5.4 + $12.74
Weighted-Average Unit Contribution Margin = $22.86