The POISSON.DIST function returns the Poisson distribution for the number of events and the indicated mean.
POISSON.DIST(
x,
mean,
cumulative
)
- x: Number of occurrences of the event.
- mean: Number of times the phenomenon is expected to occur during a given interval.
- cumulative: Logical value that determines the shape of the probability distribution. If it takes the value True, the function returns the cumulative Poisson probability that the number of random events is between zero and x included. If it takes the value False, the function returns the mass function of the probability that the number of events is exactly x.
The POISSON.DIST function returns a real number.
The POISSON.DIST function is calculated as follows. If cumulative = True:
...where λ is the mean argument.
If, on the contrary, cumulative = False:
If x is not a whole number, it is rounded.
If x or mean are not numeric values, the function returns a #VALUE! error.
If x <0 or mean <0, the function returns a #NUM! error.
For mean = 4, we can calculate the value of the Poisson distribution corresponding to x = 1 with the following measure:
distribución = POISSON.DIST(1, 4, FALSE())