Microsoft Office Tutorials and References
In Depth Information
PERMUT returns the number of permutations for a given number of objects that can be
selected from a range of numbers.
Permutations are not the same as combinations. With a combination, the numbers 1 2 3 is the
same as 3 2 1, 1 3 2, 2 3 1, and so on; permutations sees each of these as distinct outcomes.
For example, the PERMUT function will tell you how many different ways these numbers can
appear if you select 3 numbers from 1 to 3. Figure 11.36 shows the result.
Is the number of objects in the range.
Is the number of objects in each permutation.
With the PERMUT
function, each number
selected must be
unique. It accounts for
1 2 3, but not 1 1 1
or 1 1 2.
POISSON returns the Poisson distribution.
The Poisson probability distribution is applied to experiments with random and independent
occurrences. The occurrences are always considered within an inter val (time, space, or volume).
Using a known average number of occurrences for the inter val, the POISSON function computes
the probability of a certain number of occurrences at the x inter val. Figure 11.37 shows the
Poisson probability distribution for the number of people arriving at a bank branch within a one
hour time period.
Is the number of occurrences within the inter val.
Is the average and, therefore, expected number of occurrences.
Is a TRUE/FALSE value that determines the form in which the Poisson
probability distribution will be returned. If TRUE, the cumulative
probability is returned (the probability that the number of occurrences will