So one thing that you might be wondering is, well, what is a one-sample z-interval? Well, you could really interpret that as he's gonna take one sample and then construct a confidence interval based on that. The reason why it might be called a z-interval is the whole idea behind a confidence interval is you're going to pick a number of standard deviations above and below the true parameter that you are actually trying to estimate, and then use that to make your inferences. And one way of thinking about the number of standard deviations, people will often call that a z-score, or z is often used as a variable for the number of standard deviations above or below something. So really, he's just trying to construct a confidence interval. But remember, in order to construct a confidence interval, we have to make some assumptions. He's taking, there's 150 students right over here.