Business Week (Reed, Stanley, et al., “Open Season on Big Oil,” September 26, 2005) reported on data provided by A. G. Edwards & Sons concerning the profits ($billions) for 10 of the largest integrated oil and gas companies over the period from 1999 to 2005.

a. Produce a line plot of the profit versus the year.
b. Describe the types of relationships that exist between years and profits during the specified time period.
c. Which of the relationships would you use to project the companies’ profits in the year 2006? Explain your answer.