Swisher, Incorporated reports the following annual cost data for its single product: Normal production level 30,000 units Direct materials $6.40 per unit Direct labor $3.93 per unit Variable overhead $5.80 per unit Fixed overhead $150,000 in total This product is normally sold for $48 per unit. If Swisher increases its production to 50,000 units, while sales remain at the current 30,000 unit level, by how much would the company's income increase or decrease under variable costing? $60,000 decrease. $90,000 decrease. There is no change in gross margin. $90,000 increase. $60,000 increase.