STAT151 Chapter Notes - Chapter 7: Wella, Scatter Plot, Lincoln Near-Earth Asteroid Research

• School: University of Alberta
• Department: Statistics
• Course: STAT151
• Professor: Omar Rivasplata

Document Summary

7. 1: least squares: the line of best fit . The correlation says, the linear association between these two variables is fairly strong, but it doesn"t tell us how to predict one variable from the other. We can find a linear model that gives an equation of a straight line through the data. It is important to note that no straight line can go through all of the points, but a linear model can summarize the general pattern with only a couple of parameters. Like all models of the real world, the line will be wrong in the sense that it can"t match reality exactly but it can help us understand how the variables are associated. We call the estimate made from a model the predicted value, and it is written as ^y , called y-hat . The difference between the observed response and its associated predicted value is called the residual.