# BINOM.INV

The `BINOM.INV` formula calculates the smallest value for which the cumulative binomial distribution is less than or equal to a specified criterion value. It is commonly used in statistics to find the exact number of successes in a fixed number of independent trials with a known probability of success.

## Usage

Use the `BINOM.INV` formula with the syntax shown below, it has 3 required parameters:

Parameters:
1. num_trials (required):
The number of independent trials.
2. prob_success (required):
The probability of success in each independent trial, expressed as a decimal between 0 and 1.
3. target_prob (required):
The criterion value, expressed as a decimal between 0 and 1, for which to calculate the smallest number of successful trials.

## Examples

Here are a few example use cases that explain how to use the `BINOM.INV` formula in Google Sheets.

### Determine probability of winning a certain number of games in a tournament

By using `BINOM.INV`, you can determine the probability of winning exactly a certain number of games in a tournament based on the number of games played and the probability of winning each game.

### Calculate the number of defective items in a sample

If you have a sample of items from a larger population and you know the probability of a defective item, you can use `BINOM.INV` to determine the maximum number of defective items that could be in the sample, given a certain confidence level.

### Determine the minimum number of successful attempts needed

If you know the probability of success and you need to ensure that at least a certain number of attempts are successful, you can use `BINOM.INV` to determine the minimum number of attempts needed to meet your target.

## Common Mistakes

`BINOM.INV` not working? Here are some common mistakes people make when using the `BINOM.INV` Google Sheets Formula:

### Using non-numeric values for num_trials, prob_success, or target_prob

BINOM.INV requires numeric values for num_trials, prob_success, and target_prob. Check that you have entered valid numbers.

### Using a value for target_prob outside of the range 0 to 1

The target_prob must be between 0 and 1 (inclusive). Double-check that you have entered a valid value.

### Using a non-integer value for num_trials

BINOM.INV requires an integer value for num_trials. Check that you have entered a whole number.

### Using a value for prob_success outside of the range 0 to 1

The prob_success must be between 0 and 1 (inclusive). Double-check that you have entered a valid value.

### Using a negative value for num_trials, prob_success, or target_prob

BINOM.INV requires non-negative values for num_trials, prob_success, and target_prob. Check that you have entered valid values.

The following functions are similar to `BINOM.INV` 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 the `cumulative` parameter.

• `POISSON`

The `POISSON` function returns the Poisson distribution probability density function, which is used to show the probability of a certain number of events occurring in a fixed interval of time or space. It takes in the values for the number of events (x), the mean (mean), and a boolean for whether or not to return the cumulative distribution (cumulative).

• `NORM.INV`

The `NORM.INV` function returns the inverse of the cumulative normal distribution for a specified mean and standard deviation. It is commonly used in statistical analysis to find the value at which a specified percentage of observations occur below that value.

You can learn more about the `BINOM.INV` Google Sheets function on Google Support.