Discrete variable is a type of quantitative variable that only take a finite number of numerical values from the defined limits of the variable. It neglects all those values that are in decimal. Discrete variable is also known as categorical variables.
- Family members of each house in a California street are 5, 3, 6, 5 , 2, 7, 4. We can’t say family members as 4.7, 5.2, 3.5 etc…
- Number of students in a classroom are again an example of discrete variables. Because it is not possible to take 4.5, 0.5, 3.2, 9.1 values.
- Oranges in a dozen is again an example of discrete variables. Because it is not possible to take as sum of 0.5oranges.
- If two defective bulbs are to be selected from a certain lot, then the number of defective bulbs may exist as 0, 1 or 2. Number of defective bulbs cannot be 1.2, 1.7, 3, -1 etc… Therefore discrete variables only take specific values like 0, 1 and 2.
- When two dice are rolled then the number that will appear may be 1, 2, 3, 4, 5 or 6. It is not possible that the outcome will be 1.5, 5.2, 2.3 etc…
These all are the examples of discrete variable. Hence, discrete variables are used to represent data, when only whole number values are required.
Classification Of Discrete Variables
Discrete variables are further classified as;
- Nominal Variables
- Preference variables
- Multiple response Variables
- Ordinal variables