Adding standard deviation bands to simulations

[Yoshi64]

I'm using =rand() to create a weighted coin-toss simluation. I have one cell where I input the probability of heads (such at .55). Column A is 1000 cells of =rand(), while column B is just a running tally of +1 when <.55 and -1 when >.55

By doing this I can graph the results, and refresh to observe random trials. I also added an "expected value" line to my graph. However the final piece is I want to include the standard deviation bounds (parabola) for which I can expect the trials to fall within for 95% of the time or whatever. How would I go about doing this in excel?

[MrShorty]

I'm not sure how you are calculating standard deviation. Perhaps you can get the effect you want by adding and formatting error bars to your chart http://office.microsoft.com/en-us/ex...044.aspx?CTT=1