# 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.

## Usage

Use the `CHISQ.INV` formula with the syntax shown below, it has 2 required parameters:

Parameters:
1. probability (required):
The probability of the chi-squared distribution. Must be between 0 and 1, inclusive.
2. degrees_freedom (required):
The degrees of freedom of the chi-squared distribution. Must be an integer greater than or equal to 1.

## Examples

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

### Finding critical values for chi-squared tests

After performing a chi-squared test, you can use CHISQ.INV to find the critical value at a given significance level. This can help you determine whether to reject or fail to reject the null hypothesis.

### Calculating confidence intervals

CHISQ.INV can be used to calculate the confidence interval for a chi-squared distribution. This can help you estimate the range of values that a parameter is likely to fall within.

### Estimating population variance

CHISQ.INV can be used in conjunction with other statistical functions to estimate the variance of a population. This can help you understand how much variation there is in a set of data.

## Common Mistakes

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

### Incorrect probability value

One common mistake is entering a probability value outside of the range 0 to 1, which will result in an error. Double-check that the probability value is between 0 and 1 and adjust as necessary.

### Incorrect degrees of freedom value

Another mistake is entering an incorrect or invalid value for the degrees of freedom. Double-check that the degrees of freedom value is a positive integer and adjust as necessary.

### Missing or extra arguments

A common mistake is forgetting to include one or both of the required arguments in the formula, or including extra arguments that are not needed. Double-check that the formula includes exactly two arguments, separated by commas.

### Using the wrong function

Another mistake is accidentally using the wrong function, such as CHISQ.DIST instead of CHISQ.INV. Double-check that the correct function is being used for the desired calculation.

### Incorrect cell references

One final mistake is using incorrect cell references in the formula, which can cause the formula to return an incorrect result. Double-check that the correct cell references are being used in the formula.

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

• `CHISQ.DIST`

The `CHISQ.DIST` function calculates the probability density function or the cumulative distribution function of a chi-squared distribution. This function is commonly used in hypothesis testing to determine the significance of the difference between expected and observed values. The output of this function can be used to make decisions about the null hypothesis.

• `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.

• `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 `CHISQ.INV` Google Sheets function on Google Support.