Typo correction

The function we use ist $f(x)=2x+12$, not $f(x)=2x+1$.

Supporting_Notebooks/Computing_and_plotting_PDFs.ipynb

@@ -598,7 +598,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "This is what we expected. The input is the Gaussian $\\mathcal{N}(\\mu=1, \\sigma=1.4)$, and the function is $f(x) = 2x+1$. Therefore we expect the mean to be shifted to $f(\\mu) = 2*1+12=14$. We can see from the plot and the print statement that this is what happened. \n",
+    "This is what we expected. The input is the Gaussian $\\mathcal{N}(\\mu=1, \\sigma=1.4)$, and the function is $f(x) = 2x+12$. Therefore we expect the mean to be shifted to $f(\\mu) = 2*1+12=14$. We can see from the plot and the print statement that this is what happened. \n",
     "\n",
     "Before I go on, can you explain what happened to the standard deviation? You may have thought that the new $\\sigma$ should be passed through $f(x)$ like so $2(1.4) + 12=14.81$. But that is not correct - the standard deviation is only affected by the multiplicative factor, not the shift. If you think about that for a moment you will see it makes sense. We multiply our samples by 2, so they are twice as spread out as before. Standard deviation is a measure of how spread out things are, so it should also double. It doesn't matter if we then shift that distribution 12 places, or 12 million for that matter - the spread is still twice the input data.\n",
     "\n"