An excel program runs a Monte Carlo coin experiment. 10,000 coins are tossed 1000 times, with the number of times N heads appearing recorded in a table. Call the number of times N heads appear during a run of the experiment Q. The average value of Q as well as its standard deviation is calculated at the experiment's end. My question is how do I calculate the error bars for such an experiment? I am not exactly sure how to do this, and I've been trying for the last few hours to find a solution, but all attempts have been fruitless. Any help would be greatly appreciated.