Returns the onetailed probability of the chisquared distribution. The χ^{2} distribution is associated with a χ^{2} test. Use the χ^{2} 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 χ^{2} random variable.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note 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 Formulas tab, in the Formula Auditing group, click the Show Formulas button.

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) 
Onetailed probability of the chisquared distribution, for the above terms (0.050001) 
