How to calculate a correlation in a scatter chart

A scatter plot establishes a collection of data on the axes to determine a correlation between the variables s. The correlation between the variables is equal to the slope that the points collectively make in the graph. Although the points do not have a solid line with a different inclination, an artificial line through the points will approach this gradient. Computers and graphing calculators draw these lines, and calculate the gradient automatically. You can, however, do this calculation manually .

one

Draw a line that links each point of the graph. The line must have an oblong shape.

two

Draw a line through the shape, dividing it into two elongated halves, with equal areas in both zones. This line is the line of the best fit scatter chart.

3

Choose any of the two points on this line. These points may or may not be true points of dispersion. In fact, the line may or may not go through any of the original and real dispersion points.

4

Subtract the coordinates corresponding to the Y axis. If the coordinate points are, for example, (2, 9) and (4, 15), it will be as follows: 9 - 15 = -6.

5

Subtract the coordinates corresponding to the X axis. In the example: 2 - 4 = -2.

6

Divide the difference of coordinates in Y, of the difference of coordinates in X. For our case it will be: -6 / 2 = 3. This is the slope of the line and the correlation of the points evident.

• With practice, you will be able to draw lines of better view fit, without attaching the points within a form.
• This process involves a correlation. If it does not exist, the shape in step 1 will not be rectangular, and the frame will show no relationship between the variables.