CHISQ.INV function

The CHISQ.INV function in Excel returns the inverse of the chi-squared distribution for a specified probability and degrees of freedom. It is commonly used to determine the chi-squared value that corresponds to a given cumulative probability, which is helpful in hypothesis testing, especially when you’re setting significance levels for tests.

Syntax:

CHISQ.INV(probability, deg_freedom)

Arguments:

• probability: The probability associated with the chi-squared distribution (a value between 0 and 1). This represents the cumulative probability up to the chi-squared value you want to find.
• deg_freedom: The number of degrees of freedom for the chi-squared distribution (positive integer).

Example:

If you want to find the chi-squared value that corresponds to a cumulative probability of 0.95 with 10 degrees of freedom, you would use:

=CHISQ.INV(0.95, 10)

This will return the chi-squared value such that the area to the left of it under the chi-squared distribution curve is 0.95. This value can be used to compare with a test statistic in hypothesis testing (such as in chi-squared tests for independence or goodness of fit).