Meaning of Probability
What is Probability:
Probability is the possibility that something happens or not under certain conditions.
Probability comes from the Latin verb i will try which means to check and of two suffixes: -bile which means to indicate or possible and -tat indicating a quality.
Probability and Statistics
Probability is a tool that measures, expresses and analyzes the uncertainties found in a phenomenon or in chance.
In the field of probability and statistics, there are 3 methods to calculate probabilities:
- Classic method: it is calculated by dividing the number of favorable cases by the number of possible cases, all of which are equally possible. For example, the probability of getting the number 6 on a die is ⅙.
- Frequentist or relative frequency method: it is calculated by dividing the observed frequency of the event by the total number of observations. This method involves performing several times and is characterized by its repetition.
- Bayesian or subjective method: it refers to the degree of belief or personal judgment about the possibility of something happening. This premise requires coherence between the information given and the plausibility of the result. For example, we can say that it is highly unlikely that he will win the Nobel Prize in Medicine.
Some of the concepts associated with the probability calculation are:
- Sample space: These are the possibilities. The sample space of a 6-sided die, for example, is 1, 2, 3, 4, 5, and 6.
- Elemental event: it is formed by a single element. If we take the example of the die, each number is an elementary event.
- Compound event: it is formed by two or more elements.
- Safe event: It is one that is always verifiable. It corresponds to the sample space.
- Impossible event: It is one that is never verifiable and is represented by ø.
- Opposite or complementary event: it is the event that occurs when a specific event is not verified. It is formed with sample elements that do not belong to the determined event.