All are measures of dispersion around central value except-

Mode is a measure of central tendency not dispersion around central tendency. Measure of dispersion (variation) The measures of central tendency (mean, median, mode) serve to locate the center of distribution, but they do not reveal how the items are spread out on either side of the center. This characteristic of a frequency distribution is commonly referred to as dispersion. There are measures to obtain this dispersion, commonly known as measures of dispersion or measures of variation. There are two kinds of measures of dispersion - i)  Absolute measures of dispersion Indicates the amount of dispersion (variation) in terms of unit. For example, when rainfall on different days are available in mm (unit of rainfall), any absolute measure of dispersion gives the variation in rainfall in mm. In simple words, absolute measure of dispersion has a unit. ii)    Relative measures of dispersion In contrast to absolute measures, relative measures are free from the units. They are pure numbers. They are used to compare variation in two or more sets, which are having different units of measurements of observations. Absolute measure Range Quartile deviation Mean deviation Standard deviation Relative measure Co-efficient of range Co-efficient of quartile deviation Co-efficient of mean deviation Co-efficient of variation Measures of dispersion used To compare variation in two or more sets, which have same units → Absolute measures. To compare variation in two or more sets, which have different units → relative measures.