I need help with doing an incremental contribution margin of a product.

This is the information i have been provided of the product.

Estimated annual sales volume = 40,000 wrench sets

machine hours required per set = 0.5

The wholesale price per set is = $14.00

The costs per set will be:

Direct Materials = 4

direct labour = 1

overhead = 10

commission = 1.10

Fixed selling and admin costs = 0.46

total costs = 16.56

Net loss per set = - 2.56