WorksheetFunction.BetaInv Method
Returns the inverse of the cumulative distribution function for a specified beta distribution. That is, if probability = BetaDist(x,...), then BetaInv(probability,...) = x.
Syntax
expression.BetaInv(Arg1, Arg2, Arg3, Arg4, Arg5)
expression A variable that represents a WorksheetFunction object.
Parameters
| Name | Required/Optional | Data Type | Description |
|---|---|---|---|
| Arg1 | Required | Double | A probability associated with the beta distribution. |
| Arg2 | Required | Double | The Alpha parameter of the distribution. |
| Arg3 | Required | Double | The Beta parameter the distribution. |
| Arg4 | Optional | Variant | An optional lower bound to the interval of x. |
| Arg5 | Optional | Variant | An optional upper bound to the interval of x. |
Return Value
Double
Remarks
The beta distribution can be used in project planning to model probable completion times given an expected completion time and variability.
- If any argument is nonnumeric, BetaInv generates an error value.
- If alpha ≤ 0 or beta ≤ 0, BetaInv generates an error value.
- If probability ≤ 0 or probability > 1, BetaInv generates an error value.
- If you omit values for A and B, BetaInv uses the standard cumulative beta distribution, so that A = 0 and B = 1.
Given a value for probability, BetaInv seeks that value x such that BetaDist(x, alpha, beta, A, B) = probability. Thus, precision of BetaInv depends on precision of BetaDist. BetaInv uses an iterative search technique. If the search has not converged after 100 iterations, the function generates an error value.