diff --git a/ml/cc/exercises/linear_regression_taxi.ipynb b/ml/cc/exercises/linear_regression_taxi.ipynb
index 4e6d1ef..6e48f37 100644
--- a/ml/cc/exercises/linear_regression_taxi.ipynb
+++ b/ml/cc/exercises/linear_regression_taxi.ipynb
@@ -420,7 +420,7 @@
         "def make_plots(df, feature_names, label_name, model_output, sample_size=200):\n",
         "\n",
         "  random_sample = df.sample(n=sample_size).copy()\n",
-        "  random_sample.reset_index()\n",
+        "  random_sample = random_sample.reset_index()\n",
         "  weights, bias, epochs, rmse = model_output\n",
         "\n",
         "  is_2d_plot = len(feature_names) == 1\n",