In this case, it would be the sample regression line slope. But because we don't know exactly what this is, we can't figure out precisely what this is going to be from a sample, we are going to estimate it with what's known as the standard error of the statistic, and we'll go into more depth in this in future videos. And since we're estimating here, we're going to use a critical t value here, which we have studied before. And so based on your confidence level you wanna have, let's say it's 95%, based on the degrees of freedom, which we'll see will come out of how many data points we have, we can figure this out. And from our sample, we can figure this out, and we can figure this out, and then we would have constructed a confidence interval. We'll also see that you could do hypothesis testing here. You could say, hey, let's set up a null hypothesis, and the null hypothesis is going to be that there's no non-zero linear relationship, or that the true population slope of the regression line, or slope of the population regression line, is equal to zero, and that the alternative hypothesis is that the true relationship could either be greater than zero, it's a positive linear relationship, or that it's just non-zero.