# Geometric distribution Probabilities

Calculates probabilities under a Geometric distribution of parameter p which is success probability of a single event. Random Variable X counts the number of trials to get a success. Pay attention that the successful trial is included in the count.

## Geometric distribution formulas

X is a random variable that counts the number of independent trials to get a success, each trial having a probability of success p.

We denote P(X = k) the probability of doing k trials to get a success (`k >= 1`).

Warning: unlike another version where only unsuccessful trials are counted, here, we count the successful attempt which is included in k.

### Probability Density Function (PDF)

`P(X = k) = (1-p)^(k-1)*p`

### Cumulative distribution function (CDF)

`F(k) = 1-(1-p)^k` pour k entier non nul

## See also

Inverse Geometric distribution

Geometric distribution Chart

Statistics Calculators