diff --git a/education/statistics/Correlation and Regression.md b/education/statistics/Correlation and Regression.md
index 4953c26..3efc928 100644
--- a/education/statistics/Correlation and Regression.md	
+++ b/education/statistics/Correlation and Regression.md	
@@ -25,6 +25,7 @@ You can approximate the mean by trying to find the upper bound and the lower bou
 ## Correlation
 Correlation is between `-1` and `1`. Correlation near 1 means tight clustering, and correlation near 0 means loose clustering.  $r$ is -1 if the points are on a line with negative slope, $r$ is positive 1 if the points are on a line with a positive slope. As $|r|$ gets closer to 1, the line points cluster more tightly around a line.
 
+If $x$ is above average, we expect the $y$ to be above average if there's a strong correlation coefficient
 ## Calculating $r$ by hand
 Put the $x$ values into $L1$, put the $y$ values into $L2$. 
 
@@ -41,3 +42,5 @@ https://www.thoughtco.com/how-to-calculate-the-correlation-coefficient-3126228
 | -- | -- |
 | $r$ | Correlation Coefficient |
 | Linear Correlation | Measures the strength of a line |
+
+(Chapter 9, ST)
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