Northern Glass Company sells glass vases at a wholesale price of $2.50 per unit, variable cost is $1.75 per unit, and monthly fixed costs are $7,500. If current sales are 25,000 units per month, and Northern wants to increase operating income by 20%, how many additional units should be sold (to the nearest unit)? Group of answer choices 145,000 vases 62,500 vases 13,500 vases 3,000 vases None of these choices is correct