CHIDIST

See Also

Returns the one-tailed probability of the chi-squared distribution. The ^c2 distribution is associated with a ^c2 test. Use the ^c2 test to compare observed and expected values. For example, a genetic experiment might hypothesize that the next generation of plants will exhibit a certain set of colors. By comparing the observed results with the expected ones, you can decide whether your original hypothesis is valid.

Syntax

CHIDIST(x,degrees_freedom)

X is the value at which you want to evaluate the distribution.

Degrees_freedom is the number of degrees of freedom.

Remarks

If either argument is nonnumeric, CHIDIST returns the #VALUE! error value.
If x is negative, CHIDIST returns the #NUM! error value.
If degrees_freedom is not an integer, it is truncated.
If degrees_freedom < 1 or degrees_freedom ≥ 10^10, CHIDIST returns the #NUM! error value.
CHIDIST is calculated as CHIDIST = P(X>x), where X is a ^c2 random variable.

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
18.307	Value at which you want to evaluate the distribution
10	Degrees of freedom
Formula	Description (Result)
=CHIDIST(A2,A3)	One-tailed probability of the chi-squared distribution, for the above terms (0.050001)