But 10% is a nice round number. And if we look at some tangible examples, it seems to do a pretty good job. So for example, right over here, let's let x be the number of boys from three trials of selecting from a classroom of n students where 50% of the class is a boy and 50% of the class is a girl. And so what we have over here is we have a bunch of different n's. What if we have 20 students in the class? What if we have 30? What if we have 100?