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NTGAMMAPARAM

Returns parameters of the gamma distribution for the specified mean and standard deviation.

Syntax​

NTGAMMAPARAM(
    Mean,
    Stdev
)

Parameters​

  • Mean is the arithmetic mean of the distribution.
  • Stdev is the standard deviation of the distribution (Positive value).

Remarks​

Parameters are estimated as:

α=m2σ2,β=σ2m\alpha=\frac{m^2}{\sigma^2},\quad \beta=\frac{\sigma^2}{m}

where mm is mean and σ\sigma is standard deviation.

Example​

  • The example may be easier to understand if you copy it to a blank worksheet\
How to copy an example

  1. Create a blank workbook or worksheet.

  2. Select the example in the Help topic.

    Note  Do not select the row or column headers.

    Selecting an example from Help

    Selecting an example from Help

  3. Press CTRL+C.

  4. In the worksheet, select cell A1, and press CTRL+V.

  5. 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.

AB
1DataDescription
23Arithmetic mean of the distribution
31.3Standard deviation of the distribution
4FormulaDescription (Result)
5=NTGAMMAPARAM(A2,A3)Parameters of the distribution Alpha and Beta for the terms above

Note The formula in the example must be entered as an array formula. After copying the example to a blank worksheet, select the range A5:A6 starting with the formula cell. Press F2, and then press CTRL+SHIFT+ENTER.

See also​