Simpson and Kafka

“The measures of the scatterness of a mass of figures in a series about an average is called measure of variation, or dispersion”

Correlation 

“Correlation analysis deals with the association between two or more variables.” – Simpson and Kofka 

Skewness

“Measures of skewness tell us the direction and the extent of skewness. In symmetrical distribution, the Mean, Median and Mode are identical. The more the Mean moves away from the Mode, the larger the asymmetry or skewness”.