Statistics

Negative Binomial Probability Calculator

Easily calculate negative binomial probability online. Determine the probability of achieving a specific number of successes in a sequence of independent Bernoulli trials.

Input Parameters

Enter the probability of success on a single trial, the desired number of successes, and the trial number to calculate the negative binomial probability.

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Result

Negative Binomial Probability:

Probability Distribution Table

This table shows the probability of achieving exactly successes for different trial numbers, starting from the minimum required trials.

Trial Number (n)Probability

Understanding Negative Binomial Probability

The Negative Binomial Distribution models the probability of achieving a specific number of successes after a certain number of trials in a sequence of independent Bernoulli trials. Unlike the binomial distribution, the number of trials is not fixed in advance. Instead, we are interested in the probability of observing the r-th success on the n-th trial.

This calculator helps you determine the likelihood of this event, given the probability of success on a single trial (p), the desired number of successes (r), and the trial number (n) at which you want to observe the r-th success. It's widely used in scenarios where you\'re interested in the number of trials needed to achieve a certain number of successes, such as in quality control, marketing, and research studies.

Learn more about Negative Binomial Distribution on Wikipedia.

Frequently Asked Questions

What is the Negative Binomial Probability Calculator?
The Negative Binomial Probability Calculator is an online Statistics calculator. You enter your values, and it returns the answer with the steps shown so you can follow along.
How accurate is the Negative Binomial Probability Calculator?
The solver uses a math engine that avoids the floating-point rounding errors you get from most hardware calculators. For typical homework and professional calculations, the results will match what you would get by hand.
Can I use the Negative Binomial Probability Calculator for professional Statistics projects?
Yes. The math behind it is standard Statistics, so the results are reliable for professional use. That said, always double-check that your inputs are in the right format before relying on the output.
Why use the Negative Binomial Probability Calculator instead of calculating by hand?
Manual calculation is slow and error-prone, especially with multiple steps. This tool does the arithmetic for you and shows each step, so you can catch mistakes before they carry forward.
How do I format my inputs for the Negative Binomial Probability Calculator?
Type your numbers into the input fields. Leave out units and symbols unless a field specifically asks for them. The solver handles the rest.