Returns the inverse of the cumulative beta probability distribution function. That is, if probability = BETADIST(x,...), then BETAINV(probability,...) = x. The cumulative beta distribution can be used in project planning to model probable completion times given an expected completion time and variability.
Syntax
BETAINV(probability,alpha,beta,A,B)
Probability is a probability associated with the beta distribution.
Alpha is a parameter to the distribution.
Beta is a parameter to the distribution.
A is an optional lower bound to the interval of x.
B is an optional 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.
BETAINV uses an iterative technique for calculating the function. Given a probability value, BETAINV iterates until the result is accurate to within ±3x10^-7. If BETAINV does not converge after 100 iterations, the function returns the #N/A error value.
Example
|
Probability |
Alpha |
Beta |
A |
B |
Formula |
Description (Result) |
|
0.685470581 |
8 |
10 |
1 |
3 |
=BETAINV([Probability],[Alpha],[Beta],[A],[B]) |
Inverse of the cumulative beta probability density function for the parameters (2) |
