probability

Knowledge

2022

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

The study of probability makes it possible to predict the future to a certain extent.

What is probability?

The term probability comes from probable, that is, of what is most likely to occur, and is understood as the greater or lesser degree of possibility that a random event will occur, expressed 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 (in random experiments under stable conditions), and proceeds to perform theoretical calculations.

To do this, what is established by the Theory of Probability is followed, a branch of the math dedicated to the study of probability. This discipline is widely used by other natural Sciences Y social What discipline auxiliary, since it allows them to handle possible scenarios based on generalizations.

The origin of probability lies in the human need to anticipate events, and to predict the future to some extent. Thus, in his endeavor to perceive patterns and connections in the realityHe was constantly faced with chance, that is, with what lacks order.

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

Types of probability

There are the following types of probability:

  • Frequency. That which determines the number of times a phenomenon can occur, considering a certain number of opportunities, through experimentation.
  • Math. It belongs to the field of arithmetic, and aims to calculate in figures the probability that certain random events take place, from the logic formal and not your experimentation.
  • Binomial. The one 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 all probability in which we know in advance the frequency of an event, and the probable cases of the event occurring are simply disclosed.
  • Subjective. Contrary to mathematics, it is based on certain eventualities that allow inferring the probability of an event, although far from a certain or calculable probability. Hence its subjectivity.
  • Hypergeometric. That which is obtained thanks to techniques sampling, creating groups of events according to their appearance.
  • Logic. The one that has as a characteristic feature that establishes the possibility of occurrence of an event from 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

In meteorology, the probability is calculated considering multiple factors.

Probability is continually around us. The most obvious examples of it 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 rolls of the dice. Or it can be done with the lottery, although this requires such enormous calculations that it is virtually impossible to predict.

We also deal with probability when we check the weather forecast, and we are warned of a certain percentage probability of rain. Depending on the number, it will be more or less likely that it will rain, but it could happen that it does not happen, since it is a prediction, not a certainty.

Formula for calculating the 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 a percentage)

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

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

Probability applications

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

  • The analysis of risk business. According to which the possibilities of falling stock prices are estimated, and an attempt is made to predict whether or not it is appropriate to do so. investment in one or the other business.
  • Statistical analysis of the conduct. Of importance to the sociology, 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 the products or the reliability of a service (or an insured, for example), in order to know how much warranty time should be offered, or who should be insured and for how much.
  • At 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 that calculations in matter are normally carried out in probabilistic terms: it exists 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 if they are reliable or not, and whether or not they should be mass produced, or to what percentage of the population they may cause certain side effects.
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