Fix typo in 02.07-Fancy-Indexing

The second reference to `x[3]` in "You might expect that x[3] would contain the value 2, and x[3] would contain the value 3," should be x[4].

Author: ncclementi

notebooks/02.07-Fancy-Indexing.ipynb

@@ -709,7 +709,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "You might expect that ``x[3]`` would contain the value 2, and ``x[3]`` would contain the value 3, as this is how many times each index is repeated. Why is this not the case?\n",
+    "You might expect that ``x[3]`` would contain the value 2, and ``x[4]`` would contain the value 3, as this is how many times each index is repeated. Why is this not the case?\n",
     "Conceptually, this is because ``x[i] += 1`` is meant as a shorthand of ``x[i] = x[i] + 1``. ``x[i] + 1`` is evaluated, and then the result is assigned to the indices in x.\n",
     "With this in mind, it is not the augmentation that happens multiple times, but the assignment, which leads to the rather nonintuitive results.\n",
     "\n",