Wilco sells pencils for $20 per unit, has variable manufacturing costs of $5 per unit sold, variable selling costs of $1 per unit sold, total fixed manufacturing overhead of $40,000, and total fixed selling costs of $10,000. Wilco sells 10,000 units in December. If Wilco expects a 5% increase in sales in January, what change in income should Wilco expect? 6.8% 7.5% Some other answer 10% 7.8%