Speedy Lube is a car care center specializing in ten-minute oil changes. Speedy Lube has two service bays, which limits its capacity to 3,600 oil changes per month. The following information was collected over the past six months:
Month Number of Operating
Oil Changes Expenses
January................................................................................. 3,100......................$36,000
February............................................................................... 2,500......................$31,500
March................................................................................... 2,700......................$32,500
April...................................................................................... 2,600.....................$32,100
May....................................................................................... 3,500.....................$36,600
June...................................................................................... 2,800......................$33,300
1. Prepare a scatter plot graphing the volume of oil changes (x-axis) against the company's monthly operating expenses (y-axis). Graph by hand or use Excel.
2. How strong of a relationship does there appear to be between the company's operating expenses and the number of oil changes performed each month? Explain. Do there appear to be any outliers in the data? Explain.
3. Based on the graph, do the company's operating costs appear to be fixed, variable, or mixed? Explain how you can tell.
4. Would you feel comfortable using this information to project operating costs for a volume of 4,000 oil changes per month? Explain.