Best-fitting lines for points; (0.1,2.1) (.0,2.5) (2.2, 2.9) (2.9, 3.4), (4.0, 4.0), (4.9, 4.3)

Have a look at http://hotmath.com/hotmath_help/topics/line-of-best-fit.html for the formulae for fitting a least-squares best-fit line.  The graph below shows the result:

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