The LOGNORMDIST function in Google Sheets is essential for evaluating the cumulative distribution of a log-normally distributed random variable. This function is especially useful in statistics and finance when analyzing data that is not normally distributed, allowing users to model real-world phenomena effectively.

Syntax

LOGNORMDIST(x, mean, standard_deviation)

• x: The value at which you want to evaluate the cumulative distribution.
• mean: The mean (average) of the underlying normal distribution.
• standard_deviation: The standard deviation of the underlying normal distribution.

Example #1

LOGNORMDIST(10, 0, 1)

This function calculates the cumulative distribution value for a log-normal distribution where the specified value is 10, with a mean of 0 and a standard deviation of 1. The result is approximately 0.9998.

Example #2

LOGNORMDIST(5, 2, 0.5)

This represents finding the cumulative distribution for a log-normal variable with a specified value of 5, a mean of 2, and a standard deviation of 0.5, yielding a result of about 0.8737.

Example #3

LOGNORMDIST(0, 1, 0.3)

In this case, the function evaluates the cumulative distribution at a value of 0, with a mean of 1 and a standard deviation of 0.3, producing a result around 0.0478.

Error handling

• NUM!: Occurs when x is non-positive (x <= 0), as log-normal distributions are only defined for positive values.
• VALUE!: This error arises if any of the parameters are non-numeric, indicating that a valid number was expected.
• REF!: Indicates that a cell reference used in the function is invalid, which prevents the function from executing properly.

Conclusion

The LOGNORMDIST function is a powerful tool in Google Sheets for making statistical analyses simpler, particularly when dealing with variables that follow a log-normal distribution. By understanding its syntax and parameters, users can effectively apply this function to a range of practical scenarios, enabling better decision-making based on statistical inference.