We now turn our attention to some of the most widely used methods in the statistical tool kit. By the end of Part IV we will have constructed a statistical model that predicts peoples' weight (scaled data) based upon their height (scaled data) and their sex (binomial data). We'll start off by looking at a visual aid called a scatterplot (Figure 36.1). It paints a pointillist picture of the relationship between pairs of variables (, ). We'll make be peoples' heights and be peoples' weights. Each data point (, ) on the scatterplot is the height and weight of one person.