89 Cost of College In 2005 the average annual tuition and fees for attending a private college or university was 21 000 This cost rose to about 32 000 in 2015 as illustrated in the figure Source Cerulli Associates y Cost dollars 35 000 30 000 25 000 20 000 15 000 10 000 5000 a 2015 32 00 Q 2005 21 000 04 2005 2010 2015 2020 Year X Find the slope intercept form of the line passing through 2005 21 000 and 2015 32 000 Interpret the slope b Use the equation to estimate the cost of attending a private college in 2013