Test: Measures Of Dispersion - JAMB MCQ

Range is the difference between the largest value and the smallest value of a series.
Range = L- S
Here,  L= Largest value, S= Smallest value.
No other values of the series are taken into consideration in this case.

The departure of the Lorenz curve from the line of equal distribution would indicate the extent of dispersion.

Half of the Inter-Quartile Range is called Quartile Deviation. Lower the value of the quartile deviation, lower the dispersion.

A measure of dispersion can tell us about income inequalities.

The coefficient of quartile deviation (sometimes called the quartile coefficient of dispersion) allows you to compare dispersion for two or more sets of data. The formula is:
 Q3-Q1 
 Q3+Q1
100/150= 0.66

The relative measures of dispersion are expressed in percentage. These are used to compare two or more series which are expressed in different units.

S = 80

The graphical method of studying dispersion is known as Lorenz curve method. It is named after Dr. Max. O. Lorenz who used it for the first time to measure the distribution of income and wealth.

Standard deviation is the best and widely used measure of dispersion. The properties of standard deviation are:
(i) Standard deviation is rigidly defined.
(ii) It requires harder calculations.
(iii) It depends on all the values of the variable.
(iv) It is based on deviations from the arithmetic mean.
(v) It is capable of further statistical treatment.