Broke up the final presentaiton into three parts

I created a new R file based on what you did. I added the option to set the seed and to change the way the plots are generated. I also added numerous comments. A couple of notes. The integral at the beginning should be approximated using a Milstein method. Also, you should use the same time step throughout. That means that the approximation for the balance of the bond fund should use the same time step as the integral at the top.