Atlantic company produces a single product. for the most recent year, the company's net operating income computed by the absorption costing method was $7,800 and it net operating income computed by the variable costing method was $10,500, the companys unit product cost was $15 under variable costing and $24 under aborption costing. if the ending inventory consisted of 1,460 units, how many units must have been in the beginning inventory?