I’m tutoring an 8th grade student in Algebra 1, and he showed me that their class learned how to find standard deviation and mean absolute deviation using the following formulas:
$SD=\sqrt{\displaystyle\frac{\Sigma (x_i-\mu)^2}{n}}$
$\textbf{Mean Absolute Deviation}=\displaystyle\frac{\Sigma |x_i-\mu|}{n}$
I did not learn this when I was in Algebra 1 in 8th grade, and I was in the honors class. Is this because of Common Core? I know they’re trying to scatter more stats materials in the regular curriculum but I’m just shocked he was working on this at his level. He eventually understood it and was getting the correct answers but he definitely struggled a lot with it today before getting there. Just don’t understand why they’re covering this at this level — it seems a little advanced to me.