# NEGBINOM.DIST

NEGBINOM.DIST(number_f, number_s, probability_s, cumulative)

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

 number_f The number of failures. number_s The threshold number of successes. probability_s The probability of a success. cumulative A logical value indicating the type of function to use:True = cumulative probability functionFalse = probability mass function

 REMARKS
 * This function replaces the NEGBINOMDIST function.* The negative binomial distribution is a discrete distribution.* This function returns the probability that there will be "number_f" failures before the "number_s"-th success, when the constant probability of a success is "probability_s".* For example, you need to find 10 people with excellent reflexes, and you know the probability that a candidate has these qualifications is 0.3.* This function calculates the probability that you will interview a certain number of unqualified candidates before finding all 10 qualified candidates.* The "number_f" and "number_s" are truncated to integers.* If any of the arguments are not numeric, then #VALUE! is returned* If "probability_s" < 0, then #NUM! is returned.* If "probability_s" > 1, then #NUM! is returned.* If ("number_f" + "number_s" - 1) = 0, then #NUM! is returned.* The equation for the negative binomial distribution is: ??* Added in Excel 2010.* For the Microsoft documentation refer to support.microsoft.com

 A 1 =NEGBINOM.DIST(0,1,0.25,FALSE) = 0.25 2 =NEGBINOM.DIST(0,1,0.5,FALSE) = 0.5 3 =NEGBINOM.DIST(1,6,0.5,FALSE) = 0.047 4 =NEGBINOM.DIST(10,5,0.25,FALSE) = 0.055 5 =NEGBINOM.DIST(10,5,-4,FALSE) = #NUM! 6 =NEGBINOM.DIST(10,"some text",0.25,FALSE) = #VALUE!