Types Of Random Variables
Discrete & Continuous —the mighty brothers
The idea behind this post is to understand two types of random variables: Discrete Random Variables and Continuous Random Variables. If you are not familiar with what are random variables please refer the post Random Variables.
1. Discrete Random Variables
The random variables which take distinct values. For example: Consider a random variable X representing coin flip:
All possible outcome of this experiments can be listed as {0,1}. In this case, the possible outcomes of the experiment are countable. Hence this is a discrete random variable.
2. Continuous Random Variables
Continuous random variables are those variables which will take any value between a range. For example: Consider a experiment- exact weight of some random student selected from a University.
All possible outcome of this experiments can not be listed but we can define some range saying that the outcome of this experiment will fall between so and so range. In this case, the possible outcomes of this experiment are not countable. Hence this is a continuous random variable.
Few examples:
The number of dogs that are going to born in the universe tomorrow : Discrete. The exact winning time of men’s 100m dash in 2016 Olympics : Continuous. The winning time of men’s 100m dash in 2016 Olympics rounded to nearest hundreds: Discrete.
Conclusion
If we can count all the possible outcomes of a random process (or experiment) then such experiment can be represented using a discrete random variable. If we are not able to list all the possible outcomes then such experiments can be represented using continuous random variables.
Find next post Probability distributions
