A distribution provides a parameterised mathematical function that can be used to calculate the probability for any individual observation from the sample space.

The most common distributions are:

Normal Distribution

Student’s t-distribution

Geometric distribution

Bernoulli distribution

Binomial distribution

Poisson distribution

Lognormal distribution

Density Functions

Distribution are usually described in terms of their density functions:

PDF (Probability Density Function) is used to calculate the likelihood of a given observation in a distribution and can be represented as follow.

CDF (Cumulative Density Function) calculates the cumulative likelihood for the observation and all prior observations in the sample space. …