S6-8 Prepare and analyze a scatter plot (Learning Objective 3) 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 Oil Changes Operating 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 companys monthly operating expenses (y-axis). Graph by hand or use Excel. 2. How strong of a relationship does there appear to be between the companys 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 companys 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.

PLEASE ANSWER ONLY S6-9

S6-9 Use the high-low method (Learning Objective 4) Refer to the Speedy Lube data in S6-8. Use the high-low method to determine the variable and fixed cost components of Speedy Lubes operating costs. Use this information to project the monthly operating costs for a month in which the company performs 3,600 oil changes.