And if you're using a sample standard deviation and this confidence interval is all about the mean, and so our critical value here is going to be based on a t-table, on a t-statistic, and then we're gonna multiply that times the sample standard deviation of the differences divided by the square root of our sample size, divided by the square root of five. Now we know most of this data here, and let me just write it down over here. We know the mean, the sample mean right over here is 6.8, so it's going to be 6.8 plus or minus. And now what will be our critical value here? Well, we want to have a 95% confidence interval. And what's our degrees of freedom? Well, it's one less than our sample size, so our degrees of freedom right over here is equal to four.