# 3.5.3.1.14 Logncdf

## Description

Computes the probabilities of the specified tail type tail in a given value x, associated with a Lognormal distribution using the corresponding parameters mu and sigma.

## Syntax

double prob = logncdf(double x, double mu, double sigma[, int tail])

## Parameters

x

Input, the value of Lognormal variate $x > 0$

mu

Input, the mean of the associated Lognormal distribution .

sigma

Input, the standard deviation of the associated Lognormal distribution, $sigma > 0$

tail

Input, Optional. The tail probability type using for the Lognormal distribution
• 1 = the for upper tail probability
• 2 = the lower tail probability (Default if not set)
• 3 = the two tail (significance level) probability
• 4 = the two tail (confidence interval) probability

prob

Output, the returned probability.

## Example

logncdf(150,2,0.2,3)=;     // ANS: 3.2904785027465E-51