5.1.4 Linear correlation coefficient

5.1.4 Linear correlation coefficient



The linear correlation coefficient is the quotient between the covariance and the product of the standard deviations of both variables.

Properties
1.
The correlation coefficient does not change when the measurement scale does it.
That is, if we express the height in meters or in centimeters, the correlation coefficient does not change.

2.
The sign of the correlation coefficient is the same as that of the covariance.

3.
  The linear correlation coefficient is a real number between -1 and 1.

Four.
  If the linear correlation coefficient takes values close to -1, the correlation is strong and inverse, and will be stronger the closer a r approaches -1.

5.
  If the linear correlation coefficient takes values close to 1, the correlation is strong and direct, and will be stronger the closer a r approaches.

6
  If the linear correlation coefficient takes values close to 0, the correlation is weak.

7
  If r = 1 or -1, the points of the cloud are on the increasing or decreasing line. Between both variables there is functional dependence.