The data in the table below show a decrease in the average number of miles per passenger car from 2005 to 2008.
Year, x Average Number of
Miles per passenger Car
2005, 0 ................. 12,510
2006, 1 ................. 12,485
2007, 2 ................. 12,304
2008, 3 ................. 11,788
(a) Without using the regression feature on a graphing calculator, model the data with a linear function and using this function, estimate the average number of miles per passenger car in 2010 and in 2013. Answers may vary depending on the data points used.
(b) Using a graphing calculator, fit a regression line to the data and use it to estimate, to the nearest mile, the average number of miles per passenger car in 2010 and in 2013. What is the correlation coefficient for the regression line?