# LOGNORM.DIST

The `LOGNORM.DIST` function returns the cumulative distribution function (CDF) of the log-normal distribution, given a value x, a mean and a standard deviation. The log-normal distribution is often used to model values that are inherently positive and have a large range of values. The function is commonly used in financial analysis to model stock returns and in engineering to model the size of particles in a material.

## Usage

Use the `LOGNORM.DIST` formula with the syntax shown below, it has 3 required parameters:

Parameters:
1. x (required):
The numeric value at which to evaluate the distribution.
2. mean (required):
The mean of the logarithm of the distribution.
3. standard_deviation (required):
The standard deviation of the logarithm of the distribution.

## Examples

Here are a few example use cases that explain how to use the `LOGNORM.DIST` formula in Google Sheets.

### Calculating probability of stock returns

Investors can use the `LOGNORM.DIST` function to calculate the probability of stock returns based on historical data. By inputting the mean and standard deviation of a stock's past returns, investors can estimate the likelihood of future returns falling within a certain range.

### Modeling particle size distribution

In engineering, the `LOGNORM.DIST` function can be used to model the size distribution of particles in a material. By inputting the mean and standard deviation of the logarithm of the particle sizes, engineers can estimate the percentage of particles that fall within a certain size range.

## Common Mistakes

`LOGNORM.DIST` not working? Here are some common mistakes people make when using the `LOGNORM.DIST` Google Sheets Formula:

### Incorrect order of arguments

Users often provide the arguments in the wrong order, resulting in incorrect outputs. The correct order is x, mean, standard_deviation.

### Invalid input values

The function returns an error if any of the input values are negative or if the standard deviation is 0. Users should ensure that all input values are valid.

### Incorrect usage of function

Users often misunderstand the purpose of the function and use it inappropriately, resulting in incorrect outputs. The LOGNORM.DIST function is used to calculate the cumulative distribution function (CDF) for a lognormal distribution.

The following functions are similar to `LOGNORM.DIST` or are often used with it in a formula:

• `NORM.S.DIST`

The NORM.S.DIST function returns the standard normal cumulative distribution function. It calculates the probability that a random variable with a standard normal distribution is less than or equal to x. This function is commonly used in statistical analysis and hypothesis testing.

• `NORM.DIST`

The `NORM.DIST` formula is a statistical function that returns the normal distribution of a specified variable. It is used to determine the probability of a random variable falling within a specified range of values. This function is commonly used in finance and scientific research.

• `LOGNORM.INV`

The `LOGNORM.INV` function returns the inverse of the lognormal cumulative distribution for a specified mean and standard deviation. It is commonly used in statistics to model data that is skewed and has a long tail. Given a percentile value and the distribution parameters, this function calculates the corresponding value of the random variable.

• `NORM.INV`

The `NORM.INV` function returns the inverse of the cumulative normal distribution for a specified mean and standard deviation. It is commonly used in statistical analysis to find the value at which a specified percentage of observations occur below that value.

• `STDEV.P`

The `STDEV.P` function is a statistical function that calculates the standard deviation of a population based on a sample of numerical data. It is commonly used to measure the amount of variation or dispersion in a dataset. The formula assumes that the input values represent the entire population, rather than a sample. If the input values represent a sample, you should use the `STDEV.S` function instead.

You can learn more about the `LOGNORM.DIST` Google Sheets function on Google Support.