The NEGBINOM.DIST function in Excel is used to calculate the probability of success, given a certain number of trials and a certain probability of success for each trial. The function takes three arguments: the number of trials, the probability of success for each trial, and the cumulative probability. The function then returns the probability of success for the given number of trials and the given probability of success.
The syntax of NEGBINOM.DIST in Excel is =NEGBINOM.DIST(x,n,p,cumulative) where x is the number of successes, n is the number of trials, p is the probability of success, and cumulative is a logical value that specifies the type of distribution. If cumulative is FALSE (the default), NEGBINOM.DIST returns the probability of exactly x successes in n trials. If cumulative is TRUE, NEGBINOM.DIST returns the cumulative probability of at least x successes in n trials.
The Excel function for the binomial distribution is called "NEGBINOM.DIST." This function takes four arguments: the number of successes, the number of trials, the probability of success, and the probability of failure. The function will return the probability of at least k successes, where k is the number you specify as the fourth argument. An example calculation might look like this:
=NEGBINOM.DIST(5,10,0.5,0.5)
This function calculates the probability of at least 5 successes out of 10 trials, with a 50% chance of success on each trial. The result returned is 0.6875, which means that there is a 68.75% chance of getting at least 5 successes out of 10 trials when the probability of success is 50%.
NEGBINOM.DIST should not be used in Excel when the number of trials is greater than or equal to 500. When the number of trials is less than 500, NEGBINOM.DIST is accurate.
There are a few similar formulae to NEGBINOM.DIST in Excel. One is called BINOM.DIST, which is used to calculate the probability of success for a binomial distribution. Another is called POISSON.DIST, which is used to calculate the probability of an event occurring a certain number of times in a given period of time. Finally, there is the NORM.DIST function, which is used to calculate the normal distribution.