Probability (Meaning and Explanation)

We explain what probability is, its types, examples and the formula to calculate it. Also, the areas in which it can be applied.

Probability - Games of chance — The study of probability allows us to predict the future to a certain extent.

What is probability?

The term probability comes from likelythat is, that which is most likely to occur, and is understood as the greater or lesser degree of possibility that a random event will occurexpressed in a figure between 1 (total possibility) and 0 (absolute impossibility), or in percentages between 100% or 0%, respectively.

To obtain the probability of an event, the frequency with which it occurs is generally determined (in random experiments under stable conditions), and theoretical calculations are carried out.

To do this, what is established by Probability Theory is followed, a branch of mathematics dedicated to the study of probability. This discipline It is widely used by other natural and social sciences as an auxiliary disciplinesince it allows them to handle possible scenarios based on generalizations.

The origin of probability lies in the human need to anticipate eventsand to predict the future to a certain extent. Thus, in his efforts to perceive patterns and connections in reality, he constantly faced chance, that is, what lacks order.

The first formal considerations on this matter come from the 17th century, specifically from the correspondence between Pierre de Fermat and Blaise Pascal in 1654, or from the studies of Christiaan Huygens in 1657 and the Kybeia by Juan Caramuel in 1649, text now lost.

Types of probability

There are the following types of probability:

Frequent. That which determines the number of times that a phenomenon can occur, considering a certain number of opportunities, through experimentation.
Mathematics. It belongs to the field of arithmetic, and aims to calculate in figures the probability that certain random events take place, based on formal logic and not experimentation.
Binomial. That in which the success or failure of an event is studied, or any other type of probable scenario that has only two possible outcomes.
Objective. This is the name given to any probability in which we know in advance the frequency of an event, and the probable cases of said event occurring are simply made known.
Subjective. Contrasted with mathematics, it is based on certain eventualities that allow us to infer the probability of an event, although far from a certain or calculable probability. Hence its subjectivity.
Hypergeometric. That which is obtained thanks to sampling techniques, creating groups of events according to their appearance.
Logic. Which has as a characteristic feature that establishes the possibility of occurrence of a fact based on the laws of inductive logic.
Conditioned. That which is used to understand the causality between two different events, when the occurrence of one can be determined after the occurrence of the other.

Examples of probability

meteorological probability — In meteorology, probability is calculated considering multiple conditions.

Probability is continually around us. The most obvious examples of this have to do with gambling: dice, for example. It is possible to determine the frequency of appearance of each face, from a continuous series of throws of the die. Or it can also be done with the lottery, although this requires calculations so enormous that they are virtually impossible to predict.

Formula to calculate probability

The calculation of the probabilities is carried out according to the following formula:

Probability = Favorable cases / possible cases x 100 (to take it to percentage)

Thus, for example, we can calculate the probability that a coin will come up heads in a single toss, thinking that only one head (1) of the two that there are (2) can come up, that is, 1 / 2 x 100 = 50% of probability.

On the other hand, if we decide to calculate how many times the same head will come up in two consecutive tosses, we will have to think that the favorable case (heads and heads or tail and tail) is one of four possible outcomes (heads and heads, heads and tail, tail and tail). face, seal and seal). Therefore, 1/4 x 100 = 25% probability.

Applications of probability

The calculation of probability has numerous applications in everyday life, such as:

Business risk analysis. According to which the possibilities of a fall in the price of stock shares are estimated, and an attempt is made to predict the convenience or not of investing in one company or another.
The statistical analysis of behavior. Of importance to sociology, it uses probability to evaluate the possible behavior of the population, and thus predict trends of thought or opinion. It is common to see it in electoral campaigns.
The determination of guarantees and insurance. Processes in which the probability of failure of products or the reliability of a service (or of an insured, for example) is evaluated, in order to know how much warranty time should be offered, or who should be insured and for how much.
On the location of subatomic particles. According to the Heisenberg Uncertainty Principle, which states that we cannot know where a subatomic particle is at a given moment and at the same time at what speed it is moving, so calculations in matter are normally carried out in probabilistic terms: there is X percent chance that the particle is there.
In biomedical research. Percentages of success and failure of medical drugs or vaccines are calculated, in order to know whether they are reliable or not, and whether or not it is advisable to mass produce them, or to what percentage of the population they may cause certain side effects.