# NORM.S.INV

The `NORM.S.INV` function is a statistical function in Google Sheets that returns the inverse of the standard normal cumulative distribution function for a specified value. In other words, it returns the z-score that corresponds to a given probability. This function is commonly used in hypothesis testing, confidence interval estimation, and other statistical analyses.

## Usage

Use the `NORM.S.INV` formula with the syntax shown below, it has 1 required parameter:

Parameters:
1. x (required):
The value for which to calculate the z-score. Must be a probability between 0 and 1, inclusive.

## Examples

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

### Calculate a z-score for a given probability

By using the `NORM.S.INV` function, you can easily calculate the z-score that corresponds to a given probability. This can be useful in hypothesis testing, confidence interval estimation, and other statistical analyses.

### Calculate a confidence interval for a normal distribution

The `NORM.S.INV` function can be used to calculate the z-score for the lower and upper bounds of a confidence interval for a normal distribution. By multiplying the z-score by the standard error and adding/subtracting the result from the mean, you can obtain the confidence interval.

### Calculate critical values for a hypothesis test

In hypothesis testing, you often need to find the critical values that separate the rejection and non-rejection regions. By using the `NORM.S.INV` function, you can easily calculate the critical values for a given significance level and test type.

## Common Mistakes

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

### Not providing a valid numeric input

The NORM.S.INV formula expects a numeric input between 0 and 1. If a non-numeric value is provided or a value outside of this range, the formula will return an error. To correct this, ensure that the input is a valid number between 0 and 1.

### Forgetting to close the function with a parenthesis

When using the NORM.S.INV formula, it is important to ensure that the function is closed with a parenthesis. If the function is not closed properly, Google Sheets will display an error. To correct this, ensure that the function is closed with a parenthesis.

### Using a different version of the formula

There are multiple versions of the NORM.S.INV formula, including NORMSINV and NORMINV. If the wrong version is used, Google Sheets will return an error or incorrect value. To correct this, ensure that the correct version of the formula is used.

The following functions are similar to `NORM.S.INV` or are often used with it in a formula:

• `NORM.S.DIST`

The NORM.S.DIST function returns the standard normal cumulative distribution function. It calculates the probability that a random variable with a standard normal distribution is less than or equal to x. This function is commonly used in statistical analysis and hypothesis testing.

• `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.INV`

The `T.INV` function returns the inverse of the Student's t-distribution for the provided probability and degrees of freedom. This function is commonly used to calculate a critical value from the t-distribution when working with small sample sizes.

• `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.

• `CHISQ.INV`

The CHISQ.INV function returns the inverse of the right-tailed probability of the chi-squared distribution. It is commonly used in hypothesis testing where the null hypothesis is that the observed data follows a chi-squared distribution. The function returns the value of the chi-squared random variable at which the cumulative distribution function equals the given probability. This function is useful for finding critical values after performing a chi-squared test.

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