This document discusses summarizing bivariate data using scatterplots and correlation. It provides an example of fare data from a bus company that is modeled using linear and nonlinear regression. Linear regression finds a strong positive correlation between distance and fare, but the relationship is better modeled nonlinearly using the logarithm of distance. The nonlinear model accounts for 96.9% of variation in fares compared to 84.9% for the linear model.