CHIINV

See Also

Returns the inverse of the one-tailed probability of the chi-squared distribution. If probability = CHIDIST(x,...), then CHIINV(probability,...) = x. Use this function to compare observed results with expected ones to decide whether your original hypothesis is valid.

Syntax

CHIINV(probability,degrees_freedom)

Probability is a probability associated with the chi-squared distribution.

Degrees_freedom is the number of degrees of freedom.

Remarks

If either argument is nonnumeric, CHIINV returns the #VALUE! error value.
If probability < 0 or probability > 1, CHIINV returns the #NUM! error value.
If degrees_freedom is not an integer, it is truncated.
If degrees_freedom < 1 or degrees_freedom ≥ 10^10, CHIINV returns the #NUM! error value.

CHIINV uses an iterative technique for calculating the function. Given a probability value, CHIINV iterates until the result is accurate to within ± 3x10^-7. If CHIINV does not converge after 100 iterations, the function returns the #N/A error value.

Example

The example may be easier to understand if you copy it to a blank spreadsheet.

How?

Create a blank spreadsheet.
Select the example in the Help topic.

Selecting an example from Help
Press CTRL+C.
In the spreadsheet, select cell A1, and press CTRL+V.
To switch between viewing the formula that returns the result and the result in the cell, select the cell and press F2 and then ENTER, or click Commands and Options on the spreadsheet toolbar, click the Formula tab, and look in the Formula in active cell (active cell) box.

Data	Description
0.05	Probability associated with the chi-squared distribution
10	Degrees of freedom
Formula	Description (Result)
=CHIINV(A2,A3)	Inverse of the one-tailed probability of the chi-squared distribution (18.30703)