Farris Corporation, which has only one product, has provided the following data concerning its most recent month of operations Selling price Units in beginning inventory Units produced Units sold Units in ending inventory $124 0 9,100 8,700 400 Variable costs per unit: Direct materials Direct labor Variable manufacturing overhead Variable selling and administrative expense Fixed costs: Fixed manufacturing overhead Fixed selling and administrative expense $ 21 $ 63 $ 9 $ 13 $136,590 What is the net operating income (loss) for the month under variable costing? $ 9,100