WorksheetFunction.NegBinom_Dist Method
Returns the negative binomial distribution. NegBinom_Dist returns the probability that there will be number_f failures before the number_s-th success, when the constant probability of a success is probability_s. This function is similar to the binomial distribution, except that the number of successes is fixed, and the number of trials is variable. Like the binomial, trials are assumed to be independent.
Namespace: Microsoft.Office.Interop.Excel
Assembly: Microsoft.Office.Interop.Excel (in Microsoft.Office.Interop.Excel.dll)
Syntax
'Declaration
Function NegBinom_Dist ( _
Arg1 As Double, _
Arg2 As Double, _
Arg3 As Double, _
Arg4 As Boolean _
) As Double
'Usage
Dim instance As WorksheetFunction
Dim Arg1 As Double
Dim Arg2 As Double
Dim Arg3 As Double
Dim Arg4 As Boolean
Dim returnValue As Double
returnValue = instance.NegBinom_Dist(Arg1, _
Arg2, Arg3, Arg4)
double NegBinom_Dist(
double Arg1,
double Arg2,
double Arg3,
bool Arg4
)
Parameters
Arg1
Type: System.DoubleNumber_f - the number of failures.
Arg2
Type: System.DoubleNumber_s - the threshold number of successes.
Arg3
Type: System.DoubleProbability_s - the probability of a success.
Arg4
Type: System.BooleanCumulative - A logical value that determines the form of the function. If cumulative is true, NegBinom_Dist returns the cumulative distribution function; if false, it returns the probability density function.
Return Value
Type: System.Double
Remarks
For example, you need to find 10 people with excellent reflexes, and you know the probability that a candidate has these qualifications is 0.3. NegBinom_Dist calculates the probability that you will interview a certain number of unqualified candidates before finding all 10 qualified candidates:
Number_f and number_s are truncated to integers.
If any argument is nonnumeric, NegBinom_Dist returns the #VALUE! error value.
If probability_s < 0 or if probability > 1, NegBinom_Dist returns the #NUM! error value.
If number_f < 0 or number_s < 1, NegBinom_Dist returns the #NUM! error value.
The equation for the negative binomial distribution is:
Figure 1: Equation for the negative binomial distribution
.jpg "Equation for the negative binomial distribution")
where:
x is number_f, r is number_s, and p is probability_s.