# 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.

## Usage

Use the `BINOM.DIST` formula with the syntax shown below, it has 3 required parameters and 1 optional parameter:

Parameters:
1. num_successes (required):
The number of successes in the trials. Must be an integer greater than or equal to 0 and less than or equal to `num_trials`.
2. num_trials (required):
The number of trials. Must be an integer greater than or equal to 0.
3. prob_success (required):
The probability of success in each trial. Must be a decimal between 0 and 1, inclusive.
4. cumulative (optional):
A boolean value that determines whether to calculate the PMF or the CDF. If `cumulative` is true, the function calculates the CDF, which is the probability of getting up to and including `num_successes` successes. If `cumulative` is false or omitted, the function calculates the PMF, which is the probability of getting exactly `num_successes` successes.

## Examples

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

### Calculating the probability of a certain number of successes

Suppose a coin is flipped 10 times, and you want to know the probability of getting exactly 3 heads. You can use `BINOM.DIST` to calculate this probability.

### Calculating the probability of up to a certain number of successes

Suppose you want to know the probability of getting up to and including 3 heads in 10 coin flips. You can use `BINOM.DIST` with the `cumulative` parameter set to true.

### Comparing observed results to expected results

Suppose you expect a certain proportion of your customers to respond to a marketing campaign, and you want to see if the actual results match your expectations. You can use `BINOM.DIST` to calculate the probability of getting the observed number of responses or fewer, and compare this to your desired confidence level.

## Common Mistakes

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

### Misunderstanding the meaning of parameters

One common mistake is misunderstanding the meaning of the parameters. For example, the 'num_successes' parameter refers to the number of successful trials, not the probability of success.

### Using the wrong probability value

Another common mistake is using the wrong probability value. For example, using the probability of failure instead of the probability of success.

### Not using the cumulative parameter correctly

The 'cumulative' parameter can be confusing. One mistake is not using it when you should, or using it when you shouldn't.

The following functions are similar to `BINOM.DIST` or are often used with it in a formula:

• `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.

• `BINOMDIST`

The `BINOMDIST` function calculates the probability of a certain number of successes in a fixed number of trials given a constant probability of success for each trial. This function is commonly used in statistical analysis and hypothesis testing.

• `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.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 t-distribution 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.

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