Microsoft KB Archive/100121

= Microsoft Knowledge Base =

Excel: Using the BINOMDIST Function
Last reviewed: September 12, 1996

Article ID: Q100121

The information in this article applies to:


 * Microsoft Excel for Windows, versions 4.0, 4.0a, 5.0
 * Microsoft Excel for the Macintosh, version 4.0

SUMMARY
The BINOMDIST function returns the individual term binomial distribution probability.

When you use the BINOMDIST function, you make the following three assumptions:

 The outcome of each trial is only success or failure. -and- The trials are independent. -and- The probability of success is constant throughout the experiment.

MORE INFORMATION
The following is the syntax for the BINOMDIST function,

BINOMDIST(number_s,trials,probability_s,cumulative) where:

NUMBER_S is the number of successes in trials

TRIALS is the number of independent trials

PROBABILITY_S is the probability of success on each trial

CUMULATIVE is a logical value that determines the form of the function If cumulative is TRUE, then BINOMDIST returns the cumulative distribution function, which is the probability that there are at most number_s successes; if FALSE, it returns the probability mass function, which is the probability that there are number_s successes.

If number_s <0 or number_s> trials, BINOMDIST returns #NUM.

If probability_s <0 or probability_s> 1, BINOMDIST returns #NUM.

For example, in a population of software engineers, 9 out of 10 recommend 5.25-inch disks. What is the probability of choosing two engineers at random and finding that neither of them recommends 5.25-inch disks?

To calculate the following values in a BINOMDIST function,

number_s     = 0 trials       = 2 probability_s = 0.9 cumulative   = false you would use the formula, BINOMDIST(0,2,0.9,false). This formula returns a result of 0.01 or 1%.