diff --git a/education/statistics/Hypothesis Tests.md b/education/statistics/Hypothesis Tests.md
index 4365b58..675ca31 100644
--- a/education/statistics/Hypothesis Tests.md	
+++ b/education/statistics/Hypothesis Tests.md	
@@ -72,6 +72,8 @@ This test is used when you have one qualitative variable with many categories, e
 
 The $\chi^2$ curve does not follow the normal curve. It has a long right hand tail. As the degrees of freedom go up, the curves flatten out, and the hump moves out to the right. 
 
+$$ df = num_{terms} - 1 $$
+
 There will never be a $\chi^2$ statistic.
 
 Ch ($\chi$), i is pronounced khai
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