diff --git a/education/statistics/Correlation and Regression.md b/education/statistics/Correlation and Regression.md
index 3efc928..40689d5 100644
--- a/education/statistics/Correlation and Regression.md	
+++ b/education/statistics/Correlation and Regression.md	
@@ -43,4 +43,12 @@ 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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+(Chapter 9, STAT 1040)
+
+# Correlation contd.
+## Notes
+- $r$ is a pure number, and does not have units
+- $r$ does not change if you:
+	- switch the $x$ and $y$ values
+	- add the same number to every x or y value
+	- multiply each $x$ or $y$ value by a positive number
\ No newline at end of file