NEGBINOM.DIST
TheNEGBINOM.DIST
function returns the cumulative distribution probability of obtaining a certain number of failures before reaching a set number of successes in a negative binomial distribution. This function is commonly used in statistical analysis to model discrete random variables. The negative binomial distribution is often used to model the number of failures before a specified number of successes occur in a sequence of independent and identically distributed Bernoulli trials.
 How to use
NEGBINOM.DIST
formula?  Examples of using
NEGBINOM.DIST
formula NEGBINOM.DIST
formula not working? Similar formulas to
NEGBINOM.DIST
Usage
Use the NEGBINOM.DIST
formula with the syntax shown below, it has 3 required parameters:
 num_failures (required):
The number of failures to occur.  num_successes (required):
The number of successes to stop at.  prob_success (required):
The probability of a success on each trial.
Examples
Here are a few example use cases that explain how to use theNEGBINOM.DIST
formula in Google Sheets.
Probability of getting a certain number of failures before a set number of successes
You can use NEGBINOM.DIST
to find the probability of obtaining a certain number of failures before reaching a set number of successes in a negative binomial distribution.
Modeling discrete random variables
The negative binomial distribution is often used to model discrete random variables. You can use NEGBINOM.DIST
to calculate probabilities for these types of models.
Estimating probabilities of winning and losing in games
You can use NEGBINOM.DIST
to estimate the probability of winning or losing a game based on the number of failures and successes needed to win the game.
Common Mistakes
NEGBINOM.DIST
not working? Here are some common mistakes people make when using the NEGBINOM.DIST
Google Sheets Formula:
Using the wrong order of arguments
One common mistake is to input the arguments in the wrong order. For NEGBINOM.DIST, the correct order is num_failures, num_successes, prob_success.
Using a probability value outside of the range [0,1]
The prob_success argument should be a probability value between 0 and 1, inclusive. Using a value outside of this range will result in an error.
Using nonnumeric arguments
All arguments for NEGBINOM.DIST should be numeric values. Using nonnumeric values will result in an error.
Using inconsistent units for num_failures and num_successes
num_failures and num_successes should have consistent units. For example, if num_failures represents the number of failures before a specified number of successes, then num_successes should represent that specified number of successes.
Misunderstanding what the output represents
NEGBINOM.DIST calculates the probability of getting a certain number of failures before a specified number of successes. It does not calculate the probability of getting a certain number of successes after a certain number of failures.
Related Formulas
The following functions are similar to NEGBINOM.DIST
or are often used with it in a formula:

BINOM.DIST
The
BINOM.DIST
function returns the probability of a certain number of successes in a fixed number of trials given a probability of success in each trial. It is most commonly used in statistical analysis and hypothesis testing. The function can calculate either the probability mass function (PMF) or the cumulative distribution function (CDF) depending on the value of thecumulative
parameter. 
POISSON.DIST
The
POISSON.DIST
function calculates the Poisson distribution, which is a statistical distribution that shows how many times an event is likely to occur within a specified period of time, given the average rate of occurrence. This function is commonly used in probability theory to model the number of times an event occurs in a fixed interval of time or space. The resulting value represents the probability of the event occurring a certain number of times. If the cumulative argument is set to TRUE (or omitted), the function returns the cumulative distribution function; if set to FALSE, it returns the probability density function. 
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. 
T.DIST
The
T.DIST
function returns the probability of a Student's tdistribution with a specified degrees of freedom. This function is usually used in hypothesis testing to determine the probability that a sample mean is within a specified range of values.
Learn More
You can learn more about the NEGBINOM.DIST
Google Sheets function on Google Support.