Added description of how to use Jupyter Notebook

01-g-h-filter.ipynb

@@ -449,6 +449,8 @@
    "source": [
     "The exact number printed depends on your random number generator, but it should be very close to 165.\n",
     "\n",
+    "If this is your first time using Jupyter Notebook, the code below is in a *cell*. The text \"In [2]:\" labels this as a cell where you can enter input, and the number in the bracket denotes that this cell was run second. To run the cell, click on it with your mouse so that it has focus, then press CTRL+ENTER on the keyboard. As we continue you will be able to alter the code inside the cells and rerun them. Try changing the values \"160\", \"170\", and \"10000\" to some other value and run the cell. The printed output should change depending on what you entered.\n",
+    "\n",
     "This code makes one assumption that probably isn't true - that the scale is as likely to read 160 as 165 for a true weight of 165 lbs. This is almost never true. Real sensors are more likely to get readings nearer the true value, and are less and less likely to get readings the further away from the true value it gets. We will cover this in detail in the Gaussian chapter. For now, I will use without further explanation the `numpy.random.normal()` function, which will produce more values nearer 165 lbs, and fewer further away. Take it on faith for now that this will produce noisy measurements very similar to how a real scale would."
    ]
   },