Microsoft Office Tutorials and References

In Depth Information

**BETAINV**

Is a logical value that determines the form of the function. If TRUE,

then
BINDOMIST
returns the
cumulative
distribution function (the

probability that there are no more than
number_s
successes). If

FALSE, then
BINOMDIST
returns the probability mass function (the

probability that there are exactly the
number_s
successes).

CUMULATIVE

The cumulative binomial distribution (when the
cumulative
argument is TRUE) is:

The
binomial probability mass
function (when the
cumulative
argument is FALSE) is:

where

is the
COMBIN(n,x)
mathematical function, described in Chapter 10, “Math and Trigonometr y

Functions.” (1-
p) is the probability of failure and is sometimes denoted by
q.

Figure 11.3 shows an example of the
BINOMDIST
function used to calculate the probabilities

that a manufactured piece of equipment will pass a safety test. When the
cumulative

argument is FALSE, the probability is about 1% that the safety test will be passed
exactly
9 out of 10

trials. Using the TRUE
cumulative
argument, the probability is almost 100% that the safety

test will be passed in 1 to 9 of the 10 trials.

Figure 11.3

The Percent column

displays the
BINOMDIST

results formatted as a

percentage and rounded

to one decimal place.