Roughly 39% of the variation in weight in the UCI student dataset 200 Weight (in pounds) 180 10 160 140- 120 100 50 50 55 60 65 Height (in inches) 70 UCI 75 75 O falls on the least-squares regression line of weight as a function of height. O can be explained by the linear association with height. O remains unexplained after accounting for height in a linear model. O is directly caused the the student's height, in a linear pattern.