And that's just something good to know. We could of course look it up on a z-table. So this is 1.96. And so this is going to be 1.96 right over here. But what about p hat? We don't know what p hat is until we actually take the sample, but this whole question is, how large of a sample should we take? Well, remember, we want this stuff right over here that I'm now circling or squaring in this less, less bright color, this blue color.