diff --git a/education/statistics/Probability.md b/education/statistics/Probability.md
index 6cc5be7..59062b8 100644
--- a/education/statistics/Probability.md
+++ b/education/statistics/Probability.md
@@ -72,6 +72,8 @@ To make a box model, answer the following questions:
 The number of draws is the amount of events.
 The number of outcomes is the number of tickets
 In the example of a dice roll, you would create tickets 1, 2, 3, 4, 5, 6, and include the number of times you roll the die next to it.
-
+m
 The *expected value*(EV) for the *sum* of all draws is $num_{draws}*ave_{box}$. 
-The *standard error* for the sum of all draws is the 
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+The *standard error* (SE) for the sum of all draws is $\sigma_{box} \sqrt{num_{draws}}$
+
+68% of the data will be within +- 1 SE of the EV.
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