Next, we'll talk about percentiles and moments. You hear about percentiles in the news all the time. People that are in the top 1% of income: that's an example of percentile. We'll explain that and have some examples. Then, we'll talk about moments, a very fancy mathematical concept, but it turns out it's very simple to understand conceptually. Let's dive in and talk about percentiles and moments, a couple of a pretty basic concepts in statistics, but again, we're working our way up to the hard stuff, so bear with me as we go through some of this review.