# NORMINV

The `NORMINV` function returns the inverse of the normal cumulative distribution for a specified value, mean, and standard deviation. It is commonly used in statistics to find the value at which a given percentage of observations lie below that value.

## Usage

Use the `NORMINV` formula with the syntax shown below, it has 3 required parameters:

Parameters:
1. x (required):
The probability value for which you want to find the corresponding value in a normal distribution.
2. mean (required):
The arithmetic mean of the distribution.
3. standard_deviation (required):
The standard deviation of the distribution.

## Examples

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

### Finding the value for a given probability

You can use the `NORMINV` function to find the value at which a certain percentage of observations lie below that value in a normal distribution, given the mean and standard deviation.

### Creating a normal distribution chart

By using the `NORMINV` function in conjunction with other statistical functions, you can create a chart that displays a normal distribution curve for a set of data.

You can use the `NORMINV` function to determine the reorder point for an inventory item based on historical sales data and the desired service level.

## Common Mistakes

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

### Incorrect argument order

Users may accidentally switch the order of the mean and standard deviation arguments, resulting in incorrect results. Double-check the argument order and ensure that they are in the correct order.

### Incorrect input range

Users may accidentally reference an incorrect input range, resulting in incorrect results. Double-check that the input range is correct and includes all necessary data.

### Invalid input value

Users may input a non-numeric value for x, mean, or standard deviation, resulting in an error. Ensure that all input values are numeric and in the correct format.

### Incorrect standard deviation value

Users may enter an incorrect value for standard deviation, resulting in incorrect results. Double-check the standard deviation value and ensure that it is accurate.

### Divide by zero error

If the standard deviation value is zero, the formula will result in a divide by zero error. Ensure that the standard deviation value is not zero.

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

• `NORMDIST`

The `NORMDIST` function in Google Sheets calculates the normal distribution for a specified value, mean, and standard deviation. It returns the probability of a value occurring within a specified range of a normal distribution. It is commonly used in statistics, finance, and science to analyze data and make predictions.

• `NORMSDIST`

The `NORMSDIST` function returns the area under a normal distribution curve to the left of a specified value. This function is commonly used in statistics to calculate probabilities.

• `NORMSINV`

The `NORMSINV` function calculates the inverse of the standard normal cumulative distribution for a specified value of x. It is commonly used in statistical analysis to transform data from a normal distribution to a standard normal distribution with a mean of 0 and a standard deviation of 1.

• `STDEV`

The `STDEV` function calculates the standard deviation of a set of numbers. It measures the amount of variation or dispersion of a set of values from the average (mean) value. It is commonly used in statistics to determine the spread of a data set. The values can be supplied as individual cells, ranges, or constants.

• `AVERAGE`

The AVERAGE function calculates the average (arithmetic mean) of the values passed to it. It is commonly used to find the average of a range of cells containing numerical data.

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