Well, we could, remember, we're taking the sum. And we're taking each of the data points. So we'll start with the first data point, all the way to the nth data point. This lowercase n says that, hey, we're looking at the sample. If I said uppercase N, that usually denotes that we're trying to sum up everything in the population. Here we're looking at a sample of size lowercase n. And we're taking each data point. So each x sub i.