Measures of dispersion are concerned with the 'spread' of values in a set of data. Measures of dispersion supply a summary statistic describing how dispersed the values are in a sample data. That is, how far from the centre of the data do the observations tend to be? Three of the more common measures of dispersion are Range, Variance, and Standard Deviation. The Range of a set of values is the difference between the smallest and largest values in the data. It is the simplest of all the measures of dispersion. Range can sometimes be misleading, particularly if a small number of data values in a series of data are outliers while the majority of data values are clustered near to each other.

a) Range is the most reliable measure of dispersion.
b) Variance emphasizes the influence of values close to the mean.
c) Measures of dispersion focus on the central tendency of data.
d) Range can be misleading when outliers are present in the data.