Final answer:
If Sheffield Corp. accepts the special order to produce 4500 bathroom scales at $15 each, the effect on net income would be an increase of $9,000.
Step-by-step explanation:
If Sheffield Corp. accepts the special order to produce 4500 bathroom scales at $15 each, the effect on net income can be calculated. The total revenue from the order would be the number of scales multiplied by the selling price: 4500 x $15 = $67,500. The total variable cost to produce the scales would be the number of scales multiplied by the variable cost per scale: 4500 x ($12 + $1) = $58,500. The fixed costs are irrelevant since they do not change with the order. The net income from the special order would be the total revenue minus the total variable cost: $67,500 - $58,500 = $9,000.