NTGAMMADIST

Returns the gamma distribution for the specified parameters.

Syntax

NTGAMMADIST(
    x,
    Alpha,
    Beta,
    Cumulative
)

x is the value for which you want the distribution ( $x\geq 0$ ).
Alpha is a parameter of the distribution $\alpha(>0)$ .
Beta is a parameter of the distribution $\beta(>0)$ .
Cumulative is a logical value that determines the form of the function. If cumulative is TRUE, NTGAMMADIST returns the cumulative distribution function; if FALSE, it returns the probability density function.

f(x)=\frac{1}{\beta^{\alpha}\Gamma(\alpha)}\exp\left(-\frac{x}{\beta}\right)x^{\alpha-1}

, where $\Gamma(\cdot)$ is gamma function.

Cumulative distribution function is given as:
$F(x)=\frac{\Gamma_{\frac{x}{\beta}}(\alpha)}{\Gamma(\alpha)}$
, where $\Gamma_{x}(\cdot)$ is incomplete gamma function.

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 Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

	A	B
1	Data	Description
2	5	Value for which you want the distribution
3	4	Value of parameter Alpha
4	2.3	Value of parameter Beta
5	Formula	Description (Result)
6	=NTGAMMADIST(A2,A3,A4,TRUE)	Cumulative distribution function for the terms above
7	=NTGAMMADIST(A2,A3,A4,FALSE)	Probability density function for the terms above