diff --git a/module2/exo2/exercice.ipynb b/module2/exo2/exercice.ipynb
index ceffcfaa6dff4ae5f22143bdeba5a13162dba710..c9e229c3e497cb1db629619b2059c8146fed0ba8 100644
--- a/module2/exo2/exercice.ipynb
+++ b/module2/exo2/exercice.ipynb
@@ -133,19 +133,19 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 15,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "4.312369534258399\n"
+      "4.334094455301447\n"
      ]
     }
    ],
    "source": [
-    "stdX = np.std(X)\n",
+    "stdX = np.std(X,ddof = 1)\n",
     "print(stdX)"
    ]
   },