Measures of Central Tendency, Position and Dispersion

Measures of Central Tendency

The measures of central tendency are different ways of determining or indicating which value from the information is the central value.

The different measures of central tendency are:

Arithmetic mean

The mean is the average value of the distribution.

Median

The median is the score of the scale that separates the upper half of the distribution from the lower, that is to say, it divides the series of data in two equal parts.

Mode

The mode is the most repeated value in a distribution.


Measures of Position

Measures of position are different techniques that divide a set of data into equal groups.

To determine the measurement of position, the data must be sorted from lowest to highest. The different measures of position are:

Quartiles

The quartiles divide the data set into four equal parts.

Deciles

The deciles divide the data set into ten equal parts.

Percentiles

Percentiles divide the data set into one hundred equal parts.


Measures of Dispersion

The measures of dispersion report on how far the values of the distribution are from the center.

The measures of dispersion are:

Range

The range is the difference between the highest and lowest data of a statistical distribution.

Average Deviation

The average deviation is the arithmetic mean of the absolute values of the deviations from the mean.

Variance

The variance is the arithmetic mean of the squared deviations from the mean.

Standard Deviation

The standard deviation is the square root of the variance.