diff --git a/education/statistics/Correlation and Regression.md b/education/statistics/Correlation and Regression.md
index bb9882c..421b14f 100644
--- a/education/statistics/Correlation and Regression.md	
+++ b/education/statistics/Correlation and Regression.md	
@@ -71,4 +71,7 @@ https://www.thoughtco.com/how-to-calculate-the-correlation-coefficient-3126228
 - Just because a relationship exists between $x$ and $y$ *does not* mean that changes in $x$ *cause* changes in $y$.
 - If the graph is given to you already set up, you already know the response and explanatory variables.
 - The $\sigma$ line will always always have a slope of:
-$$\frac{\sigma_x}{\sigma_y}$$ 
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+$$\pm \frac{\sigma_y}{\sigma_x}$$
+- The SD line always passes through the averages for each axis.
+- Someone who is *exactly on* the SD line is the same number of SDs above or below
+Given a scatter diagram where the average of each set lies on the point $(75, 70)$, with a $\sigma_x$ of 10 and a $\sigma_y$ of 12, you can graph the SD line by going up $\sigma_y$ and right $\sigma_x$, then connecting that point (in this example, $(85, 82)$) with the mean points.
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