This chapter explains how to understand the relationship between two things through a method called linear regression. It looks at how closely two variables are linked by using data to create a straight line that shows this connection. Important things to consider when doing this analysis are the coefficient of determination and checking the leftover errors for accuracy. Another key factor is finding the best fit line through a process called least squares estimation. It's crucial to ensure that there is a logical connection between the two variables before carrying out this type of analysis. By following these steps, it's possible to figure out if there is a linear connection between the variables.