In order to calculate this, our standard deviation of this distribution, we have to know our population parameter. So pause this video and think about what we would do instead if we don't know what p is here, if we don't know our population proportion, do we have something that we could use as an estimate for our population proportion? Well, yes, we calculated p hat already. We calculated our sample proportion. And so a new statistic that we could define is the standard error. The standard error of our sample proportions. And we can define that as being equal to, since we don't know the population proportion, we're gonna use a sample proportion.