EXERCISE 4-7. Scattergraph Icom.com is interested in estimating the relationship between customer service costs and sales. The following data are available:

Customer Month Service Cost Sales May $ 6,000 $100,000 June $ 6,500 $140,000 July $ 7,300 $170,000 August $10,200 $200,000 September $10,800 $225,000 Required

a. Prepare a scattergraph of customer service cost (vertical axis) and sales (horizontal axis).

b. Comment on whether there appears to be a linear relation between cost and sales and whether any of the observations appear to be outliers.