Aim of the applet

Calculate the regression line by the method of least square. So, you need to enter the coordinates of the point by keyboard or clicking with the mouse directly on the chart. You can also evaluate the line at the point you want.

Input Data

The points for the regression calculation can be introduced by the user in two ways:

• For keyboard using the coordinates: Table presented to the left, the user can enter all the points you want.
• On the graph using the mouse: Once tapped on the blue circle with an A on it, the user can enter all the points you want by clicking on the desired position on the graph.

In both cases it is necessary that after the introduction of tap points Calculate line.

Furthermore, since Evaluate a point menu, the user has the possibility of evaluating the resulting line at any point.

Output data

In addition to the points, the graph will present the resulting line, along with its expression. In the event that the user evaluate the line at a point, this point will also be performed.

It shows the value of the percentage of straight-line fit, R.

First steps

• Draw with the mouse several points on the graph, then calculates the regression line. Appears regression coefficient R in%. If now you press the arrow with the mouse and change positions a few points, to recalculate the line changes R. How do you have to move the points to get close to the 100%?
• Consider the line y= 2x -3. Taking these points enter values in the points table and calculates the regression line for testing whether the starting.
• The heights in cm. of 5 girls of the same age are given by X = {158,162,172,174,178} and their mothers Y = {163,155,175,166,178}. Get the regression line and use it to estimate the height of the mother of a girl of 170 cm.