diff --git a/04_probability_distributions.ipynb b/04_probability_distributions.ipynb
index 1215f7e..7615ed1 100644
--- a/04_probability_distributions.ipynb
+++ b/04_probability_distributions.ipynb
@@ -748,7 +748,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "where $K$ is the number of possible outcomes, $p_k$ is the probability of the $k$th outcome, and $I_{x=k}$ is the indicator function which evaluates to 1 if $x = k$ and 0 otherwise. All porbabilties $p_k$ form a vector"
+    "where $K$ is the number of possible outcomes, $p_k$ is the probability of the $k$th outcome, and $I_{x=k}$ is the indicator function which evaluates to 1 if $x = k$ and 0 otherwise. All probabilities $p_k$ form a vector"
    ]
   },
   {