It's going to be that standard deviation divided by the square root of our sample size. And we saw many videos ago why that at least experimentally makes sense, or why it intuitively makes sense. So it's going to be the square root of 100. So it's going to be this guy divided by 10. Now, we do not know what this guy is. The only way to figure out what that guy is is to actually survey 100 million people, which would have been impossible. So to estimate the standard deviation of this, we will use our sampling standard deviation as our best estimate for the population standard deviation.