Linear Regression I
6th to 8th, High School
Plot several points in a relatively straight line, and then click Show Line. How well does the line approximate the scatterplot? Then, plot another point that does not lie along the line. How does the regression line change because of the outlier?
Plot one point on the graph and then click Show Line. Why do you think a line is not graphed?
Clear the graph and plot two points that have whole-number coordinates.
Clear the graph and plot three points. Think about a line that "fits" these three points as closely as possible.
Clear the graph. Place several points on the graph that lie roughly in a straight line, then hit Show Line. The line that appears is the regression line, which is sometimes known as the "line of best fit."
The line that is drawn is called the "least-squares regression line." Bascially, the least-squares regression line is the line that minimizes the squared "errors" between the actual points and the points on the line. This makes the line fit the points. To get a better feel for the regression line, try the following tasks.