# Relating quantile distribution and selection intensity

# What has wikipedia to say about ?

In probability and statistics, the quantile function, associated with a probability distribution of a random variable, specifies the value of the random variable such that the probability of the variable being less than or equal to that value equals the given probability. It is also called the percent-point function or inverse cumulative distribution function.

For example, the cumulative distribution function of exponential ($\lambda$) (i.e. intensity `\(\lambda\)`

and expected value (mean) `\(\frac{1}{\lambda}\)`

) is: