BETAINV

Definition

Returns the inverse of the cumulative beta probability density function for a specified beta distribution. That is, if probability = BETADIST(x,...), then BETAINV(probability,...) = x. The beta distribution can be used in project planning to model probable completion times given an expected completion time and variability.

Sample Usage

Syntax 

BETAINV(probability,alpha,beta,[A],[B]) 

The BETAINV function syntax has the following arguments:

• Probability     Required. A probability associated with the beta distribution.

• Alpha     Required. A parameter of the distribution.

• Beta     Required. A parameter the distribution.

• A     Optional. A lower bound to the interval of x.

• B     Optional. An upper bound to the interval of x.

Remarks 

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

• If alpha ≤ 0 or beta ≤ 0, BETAINV returns the #NUM! error value.

• If probability ≤ 0 or probability > 1, BETAINV returns the #NUM! 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.

In order to use the BETAINV formula, start with your edited Excellentable:

Then type in the BETAINV Formula in the area you would like to display the outcome:

By adding the values you would like to calculate the BETAINV formula for, Excellentable will generate the outcome: