BETA.DIST

BETA.DIST(x, alpha, beta, cumulative, [,A] [,B])

Returns the probability of getting less than or equal to a particular value in a beta distribution.

x	The number between A and B from the distribution.
alpha	The first parameter to the distribution.
beta	The second parameter to the distribution.
cumulative	A logical value indicating the type of function to use: True = cumulative probability function (less than) False = probability density function (equal to)
A	(Optional) The lower bound to the interval of x.
B	(Optional) The upper bound to the interval of x.

REMARKS

* Added in Excel 2010.
* This function replaces the BETADIST function and to make it more consistent with the NORMDIST function.
* The beta distribution is a continuous distribution.
* If "cumulative" = True, then the area under the curve to the left of "x" is returned. This uses the cumulative probability function.
* If "cumulative" = False, then the height of the bell shaped curve at "x" is returned. This uses the probability density function.
* If "A" is left blank, then ??
* If "B" is left blank, then ??
* All the values are greater than zero
* If the parameters are equal, the distribution is symmetrical.
* If either parameter is 1 and the other parameter is greater than 1, the distribution is J-shaped.
* If alpha is less than beta, the distribution is said to be positively skewed (most of the values are near the minimum value).
* If alpha is greater than beta, the distribution is negatively skewed (most of the values are near the maximum value).
* For the Microsoft documentation refer to support.microsoft.com

	A
1	=BETA.DIST(2,8,10,TRUE,1,3) = 0.685
2	=BETA.DIST(-2,8,10,TRUE,-5,3) = 0.282
3	=BETA.DIST(3,1,1,TRUE,2,3) = 1
4	=BETA.DIST(3,1,1,TRUE,,3) = 1
5	=BETA.DIST(3,-1,1,TRUE,2,2) = #NUM!
6	=BETA.DIST(3,1,1,TRUE,2,) = #NUM!
7	=BETA.DIST(3,1,-1,TRUE,2,2) = #NUM!
8	=BETA.DIST(3,1,1,TRUE,2,2) = #NUM!
9	=BETA.DIST(3,1,1,TRUE,2,"some text") = #VALUE!