Pearsonfylgnistuðull

Pearsonfylgnistuðull, often referred to as Pearson's correlation coefficient or the Pearson product-moment correlation coefficient, is a statistical measure used to assess the strength and direction of a linear relationship between two continuous variables. It is denoted by the Greek letter rho (ρ) for the population parameter or r for the sample statistic. The value of the Pearsonfylgnistuðull ranges from -1 to +1.

A value of +1 indicates a perfect positive linear correlation, meaning that as one variable increases, the other variable increases proportionally. Conversely, a value of -1 indicates a perfect negative linear correlation, where as one variable increases, the other decreases proportionally. A value of 0 suggests no linear correlation between the two variables.

The calculation of the Pearsonfylgnistuðull involves the covariance of the two variables divided by the product of their standard deviations. It is sensitive to outliers and assumes that the data is normally distributed and that the relationship between the variables is indeed linear. While it is a widely used measure, it is important to remember that correlation does not imply causation. A strong correlation between two variables does not necessarily mean that one causes the other; there may be other underlying factors influencing both.