näytekovarianssista
Sample covariance, or näytekovarianssi in Finnish, is a statistical measure that quantifies the degree to which two random variables change together in a sample. It is calculated from a set of paired observations. A positive sample covariance indicates that as one variable increases, the other tends to increase as well. Conversely, a negative sample covariance suggests that as one variable increases, the other tends to decrease. A sample covariance close to zero implies a weak linear relationship between the two variables.
The formula for sample covariance between two variables X and Y, based on n paired observations (x_i,
Cov(X, Y) = Σ[(x_i - x̄)(y_i - ȳ)] / (n - 1)
where x̄ and ȳ are the sample means of X and Y, respectively, and n is the number
Unlike correlation, which is a standardized measure and ranges between -1 and +1, the sample covariance is