Contribution to profit from the special order:
Contribution per slab = Selling price per slab - Cost per slab
Contribution per slab = $2,590 - ($990 + $460 + $1,190)
Contribution per slab = $2,590 - $2,640
Contribution per slab = -$50
Therefore, the contribution to profit from the special order is -$50 per slab.
Munoz should reject the special order to pour 43 slabs for $2,590 each, as it would result in a negative contribution to profit.