Least-squares regression line

Harry_the_cat

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Mar 16, 2016
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The least-squares regression line (of y on x) minimises the sum of the squares of the vertical distances between the data points and the line.
I am trying to explain to a person (with no calculus background) why this is not the same as minimising just the sum of the vertical distances (ie without squaring them).
Any ideas how I can convince them that these are not the same, and in general will lead to two different lines, without using calculus in the explanation.
 
You can have wide spread, but the sum can still be 0 if you don't square. This does not mean the points lie on the line as it would be if you squared the difference. Also let the sum just be near 0 but again with wide spreads.
 
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