Linear regression is the most basic and commonly used analytic technique. Regression estimates are used to describe data and to explain the relationship between one dependent variable and one or more independent variables. At the center of the regression analysis is the task of fitting a single line through a "cloud" of data points. But what if you were interested in, not only a single line, but other data points as well e.g., lower and upper values. Try to come up with a scenario where the objective is to evaluate an intervention (treatment, program etc) on extreme values. How would this study look?