So let's look at our t-table. So 95% confidence interval and 13 degrees of freedom. So degrees of freedom right over here. So we have 13 degrees of freedom. So that is this row right over here. And if we want a 95% confidence level, then that means our tail probability, remember, if our distribution, let me see if I'll draw it really small, little small distribution right over here. So if you want 95% of the area in the middle, that means you have 5% not shaded in, and that's evenly divided on each side, so that means you have 2 1⁄2% at the tails, 2 1⁄2%.