In 2018, X Company sold 6,100 units of its only product for $35.80 each. Unit costs were as follows: Variable manufacturing $15.60 Fixed manufacturing 2.43 Variable selling 4.52 Fixed selling 3.44 Total 25.99 In 2019, the selling price, variable costs per unit, and total fixed costs are not expected to change. Assuming a tax rate of 40%, how many units must X Company sell in 2019 in order to earn $72,000 after taxes