# CHISQ.INV

The CHISQ.INV function calculates the inverse of the chi-squared cumulative distribution function (CDF). It is useful in statistical analysis for finding the value at which the chi-squared distribution has a specified probability.

## Syntax

=CHISQ.INV(`probability`

, `degrees_freedom`

)

`probability` | The probability at which to evaluate the chi-squared distribution | ranging from 0 to 1. |

`degrees_freedom` | The number of degrees of freedom for the chi-squared distribution. | |

`[method]` | An optional argument to specify the method to use in the calculation. Defaults to 1 if omitted. |

## About CHISQ.INV

When delving into statistical analysis, particularly in the realm of chi-squared distributions, the CHISQ.INV function in Excel becomes a valuable asset. It serves as a tool to determine the inverse of the chi-squared cumulative distribution function, providing a pivotal value for specific probabilities associated with chi-squared distribution scenarios. This is particularly beneficial in hypothesis testing, goodness-of-fit tests, and confidence interval estimation in various fields such as science, engineering, and social sciences.

## Examples

Suppose you have a chi-squared distribution with 5 degrees of freedom and you want to find the value at which the probability of observing a chi-squared value lower than 0.05. The CHISQ.INV formula would be:=CHISQ.INV(0.05, 5)This will return the chi-squared value at the specified probability and degrees of freedom.

Consider a hypothesis testing scenario with a chi-squared distribution having 10 degrees of freedom. You aim to determine the value at which the probability of obtaining a chi-squared value less than 0.01. The CHISQ.INV formula would be:=CHISQ.INV(0.01, 10)This will yield the chi-squared value for the given probability and degrees of freedom, aiding in the assessment of statistical significance.

## Questions

**What does the degrees of freedom parameter represent in the CHISQ.INV function?**

The degrees of freedom parameter in the CHISQ.INV function refers to the number of degrees of freedom for the chi-squared distribution. It signifies the number of independent observations used to estimate a statistical parameter in the context of hypothesis testing and statistical inference.

**Can the CHISQ.INV function handle probabilities outside the range of 0 to 1?**

No, the CHISQ.INV function expects probabilities within the range of 0 to 1. Any probability value outside this range will not be valid for the calculation using the CHISQ.INV function.

**How does the optional method parameter in CHISQ.INV function affect the calculation?**

The optional method parameter in the CHISQ.INV function allows you to specify the method to use in the calculation. The default method is 1, but you can choose to use a different method by providing the appropriate numeric code as the method argument. However, for most cases, the default method suffices for the calculation of the inverse of the chi-squared cumulative distribution function.

## Related functions

CHISQ.DIST CHISQ.DIST.RT CHISQ.INV.RT