Variables in statistics are divided into two kinds – discrete or continuous depending on the values taken by the variable. If the variable takes only integer or whole number values then the variable is a discrete variable. For example, the population of a town is one example of a discrete variable. A town can only have a population given by a whole number. We cannot meaningfully say that a town has a population of 5645.5 people.
On the other hand, if the variable can take all possible values including fractional values such as 2.5, 3.876, etc. then the variable is a continuous variable. For example, the weight of a person is a continuous variable because the weight of a person can be equal to any fractional value. For example, a person can weigh 76.4 kilograms or any other such decimal fraction.
Age as a Variable:
Age as a Continuous Variable:
If we measure age up to the highest degree of precision then age can indeed be considered to be a continuous variable. For example, if a person is 32 years and 6 months old then we can say that the age of the person is 32.5 years. Similarly, if we were to measure a person’s age accurately by counting every hour, minute, and second then a person’s age can take any possible fractional value. For example, we can say that a person is 45.625 years old. Thus we conclude that age is indeed a continuous variable.
Age as a Variable in Real Life:
On the other hand, whenever someone asks another person’s age in real life the answer is always given in the form of a natural number. For example, a person might introduce himself and say that he is 26 years old. Since in ordinary life situations the age of a person is only considered to take integer values therefore we may treat age as a discrete variable for day-to-day real-life purposes. So we conclude that even though age is a continuous variable we may treat it as a discrete variable in day-to-day life applications.
Age measured in Months: Discrete or Continuous?
Suppose that a person is 2 years old. The age measured in months is equal to 24 months. If a person is 3 and a half years old then his age expressed in months is 42 months old. In both cases, we see that the age measured in months takes only whole number values. Since the variable takes only whole number values we conclude that age measured in months is a discrete variable.
Is Height Discrete or Continuous? Is Weight Discrete or Continuous?
Height and Weight are both prime examples of continuous variables. This is because the height and weight of a person can theoretically take any possible fractional value. For example, a person can have a height of 172.3cm. Or a person can weigh 82.56 kilograms.