GAMMADIST

The GAMMA.DIST function calculates the gamma distribution, a 2-parameter continuous probability distribution.

Sample Usage

GAMMA.DIST(4.79, 1.234, 7, TRUE)

GAMMA.DIST(A1, B1, C1, FALSE)

Syntax

GAMMA.DIST(x, alpha, beta, cumulative)

• x - The input to the gamma probability distribution function. The value at which to evaluate the function.

• alpha - The shape of gamma distribution.

• beta - The scale of the distribution.

• cumulative - Logical value that determines the form of the function.

  • If TRUE: GAMMA.DIST returns the left-tailed cumulative distribution function.
  • If FALSE: GAMMA.DIST returns the probability density function.

Notes

• x, alpha, and beta must be numeric.
• alpha and beta must be greater than zero.
• If alpha is less than or equal to 1 and cumulative is FALSE, then x must be greater than zero; otherwise, x must be greater than or equal to zero.
• GAMMA.DIST is synonymous with GAMMADIST.
• The chi-squared distribution is a special case of the gamma distribution. For an integer n > 0, GAMMA.DIST(x, n/2, 2, cumulative) is equivalent to CHISQ.DIST(x, n, cumulative).

See Also

CHISQ.DIST: Calculates the left-tailed chi-squared distribution, often used in hypothesis testing.

GAMMADIST: Calculates the gamma distribution, a two-parameter continuous probability distribution.

Example

Evaluate the probability density function of the gamma distribution at x = 5 with alpha = 3.14 and beta = 2.

	A	B	C	D
1	x	alpha	beta	solution
2	5	3.14	2	0.1276550316
4	5	3.14	2	=GAMMA.DIST(5, 3.14, 2, FALSE)
5	5	3.14	2	=GAMMA.DIST(A2, B2, C2, FALSE)