The net sales data in several years for Nike are given in the table at right. Model the data with a linear function, and predict the net sales in 2015. Answers may vary depending on the data points used.
Year, x Net Sales (in billions)
2005, 0 .......................... $13.7
2006, 1 ........................... 15.0
2007, 2 ........................... 16.3
2008, 3 ........................... 18.6
2009, 4 ........................... 19.2
2010, 5 ........................... 19.0