Google Sheets NEGBINOM.DIST Function: Syntax, Examples & Tips

num_failures:
The number of failures until the experiment is stopped.

num_successes:
The number of successes that you want to achieve.

prob_success:
The probability of success on each trial.

What is NEGBINOM.DIST?

The NEGBINOM.DIST function in Google Sheets is a statistical function used to calculate the negative binomial distribution. This distribution is useful in scenarios where you want to find the probability of a certain number of successes in a sequence of independent and identically distributed Bernoulli trials, where the trials continue until a specified number of successes is achieved.

In simpler terms, NEGBINOM.DIST helps you understand the likelihood of achieving a certain number of successes before a specified number of failures occurs.

A Practical Example

Imagine you are analyzing the performance of a sales team, and you want to determine the probability of achieving a certain number of sales (successes) before reaching a specific number of unsuccessful sales (failures).

Sales Data:

• Number of successes (k): 5 (the number of sales you want to achieve)
• Number of failures (r): 3 (the number of unsuccessful sales you are willing to tolerate)
• Probability of success (p): 0.4 (the probability of making a sale)

NEGBINOM.DIST Formula

To calculate the probability of achieving 5 sales before 3 failures, you would use the NEGBINOM.DIST function as follows:

=NEGBINOM.DIST(5, 3, 0.4, FALSE)

In this formula:

• 5 is the number of successes (k).
• 3 is the number of failures (r).
• 0.4 is the probability of success (p).
• FALSE indicates that you want the probability mass function (PMF), which gives the probability of exactly k successes.

Result of the Formula

When you apply the NEGBINOM.DIST formula, it will return the probability of achieving exactly 5 sales before 3 failures. For example, if the result is 0.179, it means there is a 17.9% chance of making exactly 5 sales before encountering 3 unsuccessful attempts.

Why Use NEGBINOM.DIST?

NEGBINOM.DIST is beneficial for analyzing scenarios involving repeated trials until a specified number of successes is reached. It is particularly useful in fields such as sales forecasting, quality control, and any situation where understanding the probability of success in a series of trials is essential.

Key Takeaways:

• NEGBINOM.DIST: A statistical function that calculates the negative binomial distribution.
• Applications: Useful for scenarios involving repeated trials until a certain number of successes is achieved.
• Probability Calculation: Helps in determining the likelihood of achieving a specific number of successes before a set number of failures.
• Common Use Cases: Ideal for sales analysis, risk assessment, and any situation requiring probability calculations in trial-based scenarios.

NEGBINOM.DIST is a valuable function for anyone working with statistical data in Google Sheets, providing insights into the probabilities of success in various scenarios.

Happy spreadsheeting!