<P> In statistics, a central tendency (or measure of central tendency) is a central or typical value for a probability distribution . It may also be called a center or location of the distribution . Colloquially, measures of central tendency are often called averages . The term central tendency dates from the late 1920s . </P> <P> The most common measures of central tendency are the arithmetic mean, the median and the mode . A central tendency can be calculated for either a finite set of values or for a theoretical distribution, such as the normal distribution . Occasionally authors use central tendency to denote "the tendency of quantitative data to cluster around some central value ." </P> <P> The central tendency of a distribution is typically contrasted with its dispersion or variability; dispersion and central tendency are the often characterized properties of distributions . Analysts may judge whether data has a strong or a weak central tendency based on its dispersion . </P>

Mean mode and median are measures of what