diff --git a/ml2/3_3_Data_Munging_with_Pandas.ipynb b/ml2/3_3_Data_Munging_with_Pandas.ipynb
index 4cf7079..16ee2b1 100644
--- a/ml2/3_3_Data_Munging_with_Pandas.ipynb
+++ b/ml2/3_3_Data_Munging_with_Pandas.ipynb
@@ -437,7 +437,7 @@
     "\n",
     "#Show mean Age, mean SibSp, and number of passengers older than 25 that survived,  grouped by Passenger Class and Sex\n",
     "df[(df.Age > 25 & (df.Survived == 1))].groupby(['Pclass', 'Sex'])['Age','SibSp','Survived'].agg({'Age': np.mean, \n",
-    "                                                                         'SibSp': np.mean, 'Survived': np.size})"
+    "                                                                         'SibSp': np.mean, 'Survived': np.sum})"
    ]
   },
   {