The NEGBINOMDIST function in Google Sheets is a powerful statistical tool that allows users to calculate the probability of observing a specific number of failures before achieving a predetermined number of successes in a series of independent trials. This function is particularly useful in fields such as finance, biology, and quality control, where understanding the distribution of failures is critical for decision-making.

Syntax

NEGBINOMDIST(f, r, p)

• f: The number of failures before achieving the desired number of successes.
• r: The number of successes to achieve.
• p: The probability of success in a single trial.

Example #1

NEGBINOMDIST(3, 2, 0.5)

This function calculates the probability of encountering 3 failures before achieving 2 successes, with a success probability of 50%. The result is approximately 0.1172.

Example #2

NEGBINOMDIST(1, 4, 0.7)

Here, the function determines the probability of having 1 failure before 4 successes, given a 70% success probability. The result is approximately 0.1021.

Example #3

NEGBINOMDIST(0, 1, 0.8)

This scenario calculates the likelihood of experiencing 0 failures before achieving 1 success, with an 80% chance of success in each trial. The result is 0.8.

Error handling

• NUM!: This error occurs if the specified number of failures or successes is negative or if the probability of success is not between 0 and 1.
• VALUE!: This error signifies that one or more arguments provided to the function are of an inappropriate type, for example, a non-numeric value.

Conclusion

In summary, the NEGBINOMDIST function is a valuable resource for statisticians and analysts in determining the probability of encountering failures before reaching a given number of successes. Its ease of use and clarity make it an integral part of data analysis in various fields. Utilizing this function can enhance your statistical modeling capabilities and support better decision-making processes.