Bates Company currently produces and sells 28,000 units of a product that has a contribution margin of $7 per unit. The company sells the product for a sales price of $25 per unit. Fixed costs are $37,100. The company has recently invested in new technology and expects the variable cost per unit to fall to $15 per unit. The investment is expected to increase fixed costs by $15,400. After the new investment is made, how many units must be sold to break-even? (Do not round intermediate calculations.)