The Best-Fitting Line

Explore regression lines and how to measure the accuracy of a regression line.

Regression lines are also known as best-fitting lines. What do we mean by best? Let’s explore the criteria that’s used in regression to determine the concept of best. Recall that, for an instructor with a beauty score of $𝑥 = 7.333$ , we mark the observed value $y$ with a circle, the fitted value $\hat y$ with a square, and the residual $y - \hat y$ with an arrow. We redisplay the top left plot of the figure below in addition to three more arbitrarily chosen course instructors:

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Getting Started with Data in R

Data Visualization

Data Wrangling

Data Importing and “Tidy” Data

Basic Regression

Multiple Regression

Statistical Inference with the infer Package

Bootstrapping and Confidence Intervals

Hypothesis Testing

Inference for Regression

Tell a Story with Data

Appendix

The Best-Fitting Line