The GAMMA.DIST function in Google Sheets is a powerful tool used for calculating the gamma distribution, which is a two-parameter continuous probability distribution. This function can help users analyze probabilities and determine likelihoods based on specific data points, making it especially useful in statistics and data analysis.

Syntax

GAMMA.DIST(x, alpha, beta, cumulative)

• x: The value at which to evaluate the distribution.
• alpha: The shape parameter of the distribution.
• beta: The scale parameter of the distribution.
• cumulative: A logical value that determines the form of the function. If TRUE, it returns the cumulative distribution function; if FALSE, it returns the probability density function.

Example #1

=GAMMA.DIST(5, 2, 1, FALSE)

This function calculates the probability density of the gamma distribution at x = 5, with an alpha (shape) of 2 and a beta (scale) of 1. The result is approximately 0.0337.

Example #2

=GAMMA.DIST(10, 3, 2, TRUE)

In this example, the function evaluates the cumulative gamma distribution up to x = 10, with an alpha of 3 and a beta of 2, resulting in approximately 0.8571.

Example #3

=GAMMA.DIST(7, 5, 1, FALSE)

Here, the function computes the probability density at x = 7 for a gamma distribution with an alpha of 5 and a beta of 1, yielding a result of approximately 0.0350.

Error handling

• NUM!: Occurs when alpha or beta parameters are non-positive. Ensure both parameters are greater than zero.
• VALUE!: Appears if the input for x is non-numeric. Check that x is a number.
• REF!: Indicates that a cell reference is invalid or does not exist. Confirm all cell references are correctly specified.

Conclusion

The GAMMA.DIST function is an essential tool for statistical analysis, allowing users to calculate both the probability density and cumulative distribution of the gamma distribution. By properly utilizing this function, researchers and data analysts can gain valuable insights from their data, enhancing their decision-making processes.