Cullumber Repairs has 200 auto-maintenance service outlets nationwide. It performs primarily two lines of service: oil changes and brake repair. Oil change-related services represent 70% of its sales and provide a contribution margin ratio of 20%. Brake repair represents 30% of its sales and provides a 30% contribution margin ratio. The company's fixed costs are $15,550,300 (that is, $77,752 per service outlet). Sales mix is determined based upon total sales dollars.