This document provides an overview of line of best fit and linear regression. It defines key concepts like linear regression, residuals, and scatter plots. It explains how to determine the line of best fit for a data set by finding the line that minimizes the sum of the squared residuals. An example is worked through showing how to calculate the line of best fit and make a prediction based on that line. The document emphasizes that linear regression is useful for understanding relationships between variables in fields like business and medical research.