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# WorksheetFunction.NormInv Method

Office 2010

Returns the inverse of the normal cumulative distribution for the specified mean and standard deviation.

Namespace:  Microsoft.Office.Interop.Excel
Assembly:  Microsoft.Office.Interop.Excel (in Microsoft.Office.Interop.Excel.dll)

## Syntax

```double NormInv(
double Arg1,
double Arg2,
double Arg3
)
```

#### Parameters

Arg1
Type: System.Double

Probability - a probability corresponding to the normal distribution.

Arg2
Type: System.Double

Mean - the arithmetic mean of the distribution.

Arg3
Type: System.Double

Standard_dev - the standard deviation of the distribution.

#### Return Value

Type: System.Double

## Remarks

Important

This function has been replaced with one or more new functions that may provide improved accuracy and whose names better reflect their usage. This function is still available for compatibility with earlier versions of Excel. However, if backward compatibility is not required, you should consider using the new functions from now on, because they more accurately describe their functionality. For more information about the new function, see the Norm_Inv(Double, Double, Double) method.

If any argument is nonnumeric, NormInv returns the #VALUE! error value.

If probability < 0 or if probability > 1, NormInv returns the #NUM! error value.

If standard_dev ≤ 0, NormInv returns the #NUM! error value.

If mean = 0 and standard_dev = 1, NormInv uses the standard normal distribution (see NormSInv(Double)).

Given a value for probability, NormInv seeks that value x such that NORMDIST(x, mean, standard_dev, TRUE) = probability. Thus, precision of NormInv depends on precision of NormDist(Double, Double, Double, Boolean). NormInv uses an iterative search technique. If the search has not converged after 100 iterations, the function returns the #N/A error value.