Update Customer Churn.ipynb
Spelling correction
"churn_data = churn_data.set_index('customerID')\n",
"churn_data = churn_data.drop(['TotalCharges'], axis=1)\n",
"\n",
- "# The dataset is naturally heirarchical: some columns only apply to some users. Ex, if you don't have internet \n",
+ "# The dataset is naturally hierarchical: some columns only apply to some users. Ex, if you don't have internet \n",
"# then the column OnlineBackup isn't applicable, as it's value is \"No internet service\". We \n",
"# are going to map this back to No. We will treat the hierachical nature by stratifying on the \n",
"# different services a user may have. \n",
