As part of her year-end responsibilities, Carol prepared the company's variable costing income statement as follows. Sales Variable expenses: $346,500 COGS $138,600 Operating expenses 23,100 161,700 Contribution margin 184,800 Fixed expenses: MOH 47,520 Operating expenses 80,000 127,520 Operating income $57,280 She hadn't been able to compare the income to last year's income yet, but she was expecting it to be lower because sales volume was down slightly from the prior year. Still, this year the company managed to produce 7,900 units, which was 700 units more than it had originally budgeted. Carol also included the following detail on her worksheet to support this income statement: variable operating expenses were $3 per unit, and there were no price or efficiency variances within the standard costing system this period.