What is the purpose of a regression line? to connect all the points in a scatterplot to show the general tendency of the points in a scatterplot to provide a scale for the x-coordinates of the points in a scatterplot to provide a scale for the y-coordinates of the points in a scatterplot

In statistics, linear regression or linear adjustment is a mathematical model used to approximate the dependency relationship between a dependent variable Y, the independent variables Xi and a random term ε.
 The regression lines are the lines that best fit the point cloud (or also called the scatter diagram) generated by a binomial distribution.

  
 to show the general tendency of the points in a scatterplot