Apple iWork '09 - Manual (Page 275)

Chapter 10 Statistical Functions 275
NEGBINOMDIST
The NEGBINOMDIST function returns the negative binomial distribution.
NEGBINOMDIST(f-num, s-num, prob-success)
 f-num: The number of failures. f-num is a number value and must be greater than
or equal to 0.
 s-num: The number of successful trials or tests. s-num is a number value that must
be greater than or equal to 1.
 prob-success: The probability of success for each trial or test. prob-success is a
number value that must be greater than 0 and less than 1.
Usage Notes
NEGBINOMDIST returns the probability that there will be a specified number of Â
failures, f-num, before the specified number of successes, s-num. The constant
probability of a success is prob-success.
Example
=NEGBINOMDIST(3, 68, 0.95) returns 0.20913174716192.
Related Topics
For related functions and additional information, see:
“BINOMDIST” on page 238
“CRITBINOM” on page 252
“PERMUT” on page 281
“PROB” on page 282
“Listing of Statistical Functions” on page 225
“Value Types” on page 36
“The Elements of Formulas” on page 15
“Using the Keyboard and Mouse to Create and Edit Formulas” on page 26
“Pasting from Examples in Help” on page 41