What Does discrete variable Mean
The variables are symbols that can acquire different values and appear in formulas, algorithms, functions and propositions of mathematics and statistics. According to their particularities, they are classified in different ways.
There are random variables , dependent variables , independent variables , variables qualitative , quantitative variables and continuous variables , among others. This time we will refer to the discrete variables .
It is interesting to know the etymological origin of the two words that give shape to the term that now occupies us:
-Variable derives from Latin, more exactly from “variabilis” which is the result of the sum of two elements of that language: the verb “variare ", Which can be translated as" change of appearance ", and the suffix" -able ", which is used to indicate" possibility ".
-Discrete, on the other hand, also comes from Latin. In his case, it is the result of the union of two other components: the prefix "dis-", which is used to specify "separation", and the verb "cernere", which can be translated as "separate" or "sift".
A discrete variable is one that is able to adopt values from a given numerical set . That is, it only acquires values from a set, not just any value.
There is a distance between the potentially observable values of a discrete variable that is impossible to “complete” with intermediate values. Therefore, between two values there is at least one value that is not observable.
The number of cars a person has is a discrete variable. A man may have, for example, one car , two cars, or three cars , to name a few possibilities. But you cannot have 1.6 cars or 2.8 cars .
In a similar sense, the number of a woman's children is also a discrete variable. You can have 2 , 4 or 6 children , never 2.1 or 5.78 children .
Many others are the examples of discrete variables that can be used to understand them. Specifically, among these are the following:
-The gender of the human being, which will be female or male.
-The number of students in a class. And it is that there may be 15, 20 or 30 students, but not 15.3 or 20.8.
-The number of fouls that can be whistled by the referee in a soccer match.
-The number of radio or television channels you have at home.
-The number of workers who make up the workforce of a company.
On the other hand, continuous variables can acquire any value in an interval, always existing other intermediate values between two observable values. The existence of more or less values depends on the precision of the measurement. For example: the height of a child can be 1.2 meters , 1.24 meters or 1.249 meters according to how it is measured. This implies that certain measurement errors are recorded.
On the contrary, with regard to continuous variables, we can make use of other examples to understand them:
-The weight of a man or a woman.
-The weight of the peaches that have been bought in the market.
-The speed that a car reaches.
-The width of a person's waist.