What equation models the data? what are the domain and range of the equation? do you think your equation is a good fit for the data?

2005 2.63
2006 3.26
2007 3.54
2008 3.769
2009 2.13
2010 2.956
2011 4.259
2012 4.16
2013 3.78
2014 3.99
2015 3.10

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

step-by-step explanation: