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 in order 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.

Given a value for probability, CHIINV seeks that value x such that CHIDIST(x, degrees_freedom) = probability. Thus, precision of CHIINV depends on precision of CHIDIST. CHIINV uses an iterative search technique. If the search has not converged 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 worksheet.

Show How?

Create a blank workbook or worksheet.
Select the example in the Help topic. Do not select the row or column headers.

Selecting an example from Help
Press CTRL+C.
In the worksheet, select cell A1, and press CTRL+V.
To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

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A	B
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)