The mean earnings (in dollars) of workers 18 years and over, by educational attainment, have increased steadily over the years and are given in the following table. Let x equal the number of years since 2000.

(a) Plot the data for high school graduates and for workers with a bachelor’s degree. Do the data points lie in a linear pattern?
(b) Find an equation for the least squares line for the mean earnings of high school graduates. Calculate and interpret the correlation coefficient.
(c) Based on your answer from part (b), at approximately what rate are the mean earnings of high school graduates growing per year?
(d) Find an equation for the least squares line for the mean earnings of workers with a bachelor’s degree. Calculate and interpret the correlation coefficient.
(e) Based on your answer from part (d), at approximately what rate are the mean earnings of workers with a bachelor’s degree growing per year?
(f) If these trends continue linearly, in what year will the mean earnings for high school graduates exceed $80,000? In what year will workers with a bachelor’s degree exceed $80,000?

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High School Year Graduate Bachelor's Degree 2003 27,915 51,206 2004 28,645 2005 29,448 2006 31,071 2007 31,286 2008 31,283 2009 30,627 2010 30,999 High School Bachelor's Degree 59,415 60,159 59,661 62,466 Year Graduate 2011 32,493 51,554 2012 32,630 54,689 2013 32,881 56,788 2014 34,099 57,181 2015 35,615 58,613 2016 36,702 56,665 2017 38,145 57,619 65,482 67,267 67,763