Probability Distributions

Probability Distributions

Published by: Anu Poudeli

Published date: 21 Jun 2023

Probability Distribution

The fields of statistics and probability theory both heavily rely on probability distributions. The likelihood of various outcomes in a random experinment or a data-generating process is mathematically described by them.

Here are a few probability distributions that are frequently seen :

1. Uniform Distributions :  All events within a given range have an equal probability according to the uniform distribution. For instance,choosing a random number between 0 and 1 is an example of a continuous uniform distribution, whereas rolling a fair six sided die is an example of a discrete uniform distribution.

2. Bernouli Distribution : The Bernouli distribution represents a binary result (such ass success or failure) with a fixed probability of success, usually abbreviated as p. It is frequently employed in situations with only two possible outcomes, such as coin tosses or manufacturing flaws.

3. Binomial Distribution : The number of successes in a fixed number of independent Bernouli trails is modeled using the binomial distribution. The two factors that define it are n, the number of trails, and p, the likelihood that each trial will be successful. In scenarios involving categorical data or counting the occurence of events, the binomial distribution is frequently used.

4. Poisson Distribution : The poisson distribution predicts the number of events that take place over a particular period of time or space. Its only distinguishing feature is the parameter (lambda), which denotes the typical rate of event occurrence.The number of customers who arrive at a service counter in a specific time period is one example of a rare occurence that the poisson distribution is frequently used to model.

5. Normal Distribution : One of the most often used probability distribution is the normal distribution (also known as the Gaussian distribution ). It is distinguished by its bell-shaped curve, which is entirely influenced by the mean and standard deviation. The distribution of many natural occurrences, including heights and test results, is often normal.

6. Exponential Distribution : In a poisson process, where events happen constantly and independently at a fixed average rate, the exponential distribution characterizes the intervals  between events. Its only distionguishing feature is the rate parameter, represented by the single parameter (lambda). In reliability analysis and queing theory, the exponential distribution is frequently utilized.

7. Gamma Distribution : The time until the event in a poissom process is modelled using the gamma distribution, which is a generalization of the exponential distribution. Shape and pace are the two factors that define it . Applications of the gamma distribution can be found in physics, engineering, and finance, among other discipines.

8. Beta Distribution : The beta distribution is a flexible distribution that is on the range [ 0,1]. It is distinguished by two shape parameters, commonly written as and. The bete distribution can be used to model probabilities and proportions and is frequently used as a prior distribution in Bayesian analysis.

These are only a few illustrations of probability distributions : there are many more , each with special characteristics and uses. Understanding probability distributions is essential for data analysis,forecasting, and making defensible choices in a variety of professions.