Oriole Airways Inc., a small two-plane passenger airline, has asked for your assistance in some basic analysis of its operations. The planes seat 10 passengers each, and they fly commuters from Oriole's base airport to the major city in the province, Metropolis. Each month, 40 round-trip flights are made. Shown below is a recent month's activity in the form of a cost-volume-profit income statement. Fare revenues (400 fares) $49,600 Variable costs Fuel $20,490 Snacks and drinks 1,300 Landing fees 1,800 Supplies and forms 1.210 24,800 Contribution margin 24,800 Fixed costs Depreciation 2.610 Salaries 12.310 Advertising 2,010 Airport hangar fees 1,670 18.600 Operating income $6,200