Different types of Variables

Introduction:

Quantities such as height, weight, age, amount can have several different values. Quantities which can assume different numerical values are called variables. A variable is any alphabet or combination of alphabets that contain the constant value. It can be vary. For example the speed of the vehicles is a variable. Variables with similar roles are mentioned with consecutive alphabets.

Variables are of two types:

(a) Continuous

(b) Discrete.

Continuous Variable

Consider an example. A person was asked to measure the thickness of a coin. He recorded the following readings:

(i) 0.2 cm with ruler

(ii) 0.23 cm with vernier

(iii) 0.231 cm with micrometer

The accuracy of thickness of the coin depended on the instrument used for measuring the thickness. Thus the thickness of the coin is a continuous variable. Variables like height, weight, time are also called continuous variables.

Discrete variable

Consider an example: The number of pupils in a class can be 30, 34, 40. But it cannot be 30.2, 35.1, because number of pupils can be expressed only as a whole number. Such numerical as number of children, trees, sheep are called discrete variables.