Fix typo: reprsented -> represented (fastai#390)

07_sizing_and_tta.ipynb

@@ -827,7 +827,7 @@
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    "metadata": {},
    "source": [
-    "The third image is built by adding 0.3 times the first one and 0.7 times the second. In this example, should the model predict \"church\" or \"gas station\"? The right answer is 30% church and 70% gas station, since that's what we'll get if we take the linear combination of the one-hot-encoded targets. For instance, suppose we have 10 classes and \"church\" is represented by the index 2 and \"gas station\" is reprsented by the index 7, the one-hot-encoded representations are:\n",
+    "The third image is built by adding 0.3 times the first one and 0.7 times the second. In this example, should the model predict \"church\" or \"gas station\"? The right answer is 30% church and 70% gas station, since that's what we'll get if we take the linear combination of the one-hot-encoded targets. For instance, suppose we have 10 classes and \"church\" is represented by the index 2 and \"gas station\" is represented by the index 7, the one-hot-encoded representations are:\n",
     "```\n",
     "[0, 0, 1, 0, 0, 0, 0, 0, 0, 0] and [0, 0, 0, 0, 0, 0, 0, 1, 0, 0]\n",
     "```\n",