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GAMMAINV
Returns the inverse of the gamma cumulative distribution. If p = GAMMADIST(x,...), then GAMMAINV(p,...) = x.
You can use this function to study a variable whose distribution may be skewed.
Syntax
GAMMAINV(probability,alpha,beta)
Probability is the probability associated with the gamma distribution.
Alpha is a parameter to the distribution.
Beta is a parameter to the distribution. If beta = 1, GAMMAINV returns the standard gamma distribution.
Remarks
- If any argument is nonnumeric, GAMMAINV returns the #VALUE! error value.
- If probability < 0 or probability > 1, GAMMAINV returns the #NUM! error value.
- If alpha ≤ 0 or if beta ≤ 0, GAMMAINV returns the #NUM! error value.
- If beta ≤ 0, GAMMAINV returns the #NUM! 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 |
|---|---|
| 0.068094 | Probability associated with the gamma distribution |
| 9 | Alpha parameter to the distribution |
| 2 | Beta parameter to the distribution |
| Formula | Description (Result) |
| =GAMMAINV(A2,A3,A4) | Inverse of the gamma cumulative distribution for the above terms (10) |