diff --git a/module2/exo4/data.csv b/module2/exo4/data.csv
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/module2/exo4/data.txt b/module2/exo4/data.txt
new file mode 100644
index 0000000000000000000000000000000000000000..3dc28308c68512f669ddcb0e88cd9e1fa3c5c0ea
--- /dev/null
+++ b/module2/exo4/data.txt
@@ -0,0 +1,100 @@
+1.400000000000000000e+01
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diff --git a/module2/exo4/exercice.ipynb b/module2/exo4/exercice.ipynb
index 0bbbe371b01e359e381e43239412d77bf53fb1fb..f7d915f22e9be6ad364a6dac95103ea6ec8278d7 100644
--- a/module2/exo4/exercice.ipynb
+++ b/module2/exo4/exercice.ipynb
@@ -1,5 +1,149 @@
 {
- "cells": [],
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# A report on new breakthrough data"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Storing data on an external file"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import numpy as np\n",
+    "\n",
+    "data = [\n",
+    "    14.0, 7.6, 11.2, 12.8, 12.5, 9.9, 14.9, 9.4,\\\n",
+    "    16.9, 10.2, 14.9, 18.1, 7.3, 9.8, 10.9,12.2,\\\n",
+    "    9.9, 2.9, 2.8, 15.4, 15.7, 9.7, 13.1, 13.2,\\\n",
+    "    12.3, 11.7, 16.0, 12.4, 17.9, 12.2, 16.2, 18.7,\\\n",
+    "    8.9, 11.9, 12.1, 14.6, 12.1, 4.7, 3.9, 16.9,\\\n",
+    "    16.8, 11.3, 14.4, 15.7, 14.0, 13.6, 18.0, 13.6,\\\n",
+    "    19.9, 13.7, 17.0, 20.5, 9.9, 12.5, 13.2, 16.1,\\\n",
+    "    13.5, 6.3, 6.4, 17.6, 19.1, 12.8, 15.5, 16.3,\\\n",
+    "    15.2, 14.6, 19.1, 14.4, 21.4, 15.1, 19.6, 21.7,\\\n",
+    "    11.3, 15.0, 14.3, 16.8, 14.0, 6.8, 8.2, 19.9,\\\n",
+    "    20.4, 14.6, 16.4, 18.7, 16.8, 15.8, 20.4, 15.8,\\\n",
+    "    22.4, 16.2, 20.3, 23.4, 12.1, 15.5, 15.4, 18.4,\\\n",
+    "    15.7, 10.2, 8.9, 21.0\n",
+    "]\n",
+    "\n",
+    "np.savetxt(\"data.txt\", data)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Analyzing results"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "scrolled": true
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Requirement already satisfied: tabulate in /opt/conda/lib/python3.6/site-packages (0.8.7)\r\n"
+     ]
+    }
+   ],
+   "source": [
+    "! pip install tabulate"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/html": [
+       "<table>\n",
+       "<tbody>\n",
+       "<tr><td>Mean  </td><td style=\"text-align: right;\">14.113  </td></tr>\n",
+       "<tr><td>Min   </td><td style=\"text-align: right;\"> 2.8    </td></tr>\n",
+       "<tr><td>Max   </td><td style=\"text-align: right;\">23.4    </td></tr>\n",
+       "<tr><td>Median</td><td style=\"text-align: right;\">14.5    </td></tr>\n",
+       "<tr><td>Std   </td><td style=\"text-align: right;\"> 4.33409</td></tr>\n",
+       "</tbody>\n",
+       "</table>"
+      ],
+      "text/plain": [
+       "<IPython.core.display.HTML object>"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    }
+   ],
+   "source": [
+    "from IPython.display import HTML, display\n",
+    "import tabulate\n",
+    "from typing import List, Any\n",
+    "\n",
+    "def display_table(table: List[List[Any]]):\n",
+    "    return display(HTML(tabulate.tabulate(table, tablefmt='html')))\n",
+    "    \n",
+    "    \n",
+    "display_table([\n",
+    "    [\"Mean\", np.mean(data)],\n",
+    "    [\"Min\", np.min(data)],\n",
+    "    [\"Max\", np.max(data)],\n",
+    "    [\"Median\", np.median(data)],\n",
+    "    [\"Std\", np.std(data, ddof=1)]\n",
+    "])"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Display results"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "<Figure size 640x480 with 2 Axes>"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    }
+   ],
+   "source": [
+    "import matplotlib.pyplot as plt\n",
+    "fig, subs = plt.subplots(2)\n",
+    "subs[0].plot(data)\n",
+    "subs[0].grid(True, linestyle=\":\")\n",
+    "subs[1].hist(data)\n",
+    "subs[1].grid(True, linestyle=\":\")\n",
+    "plt.show()"
+   ]
+  }
+ ],
  "metadata": {
   "kernelspec": {
    "display_name": "Python 3",
@@ -16,10 +160,9 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.3"
+   "version": "3.6.4"
   }
  },
  "nbformat": 4,
  "nbformat_minor": 2
 }
-