We figured out the sample mean right over here. We've figured out an estimate for the, and remember, this is just a sampling mean. We don't know the true, this is the mean of our sample. We don't know the true mean of the sampling distribution. And we also don't know the true standard deviation of the sampling distribution. But we were able to estimate it with the sample standard deviation. Now, everything that we have so far, and based on what we've seen before on confidence intervals and all of that, how can we find an interval such that roughly, and I'm saying roughly because we had to estimate the standard deviation, that there's a 95% chance that the true mean of our population, or that p, the proportion of the population saying 1, is in that interval.