CALC 1 Home Documentation Home Contact

Poisson Distribution CDF Calculator

Calculates the Poisson cumulative distribution function.


Formula: poisson(fcK, fcLam, 1)

See the Statistical Distributions Overview page for more statistical distribution calculators.

Example 1

For a Poisson distribution with a mean of 4, calculate the probability of P(X <= 8)

Value Keystrokes Display Description
4.0 λ 4.0 Stores the λ value.
8 k 8.0 Stores the k value.
  cdf 0.9786 Calculates the cdf.

Example 2

Given that the number of customers arriving per hour at a business is a Poisson distribution, if the probability of 3 or fewer customers arriving is 0.5, what is the mean?

Value Keystrokes Display Description
.5 cdf 0..5 Stores the cdf value.
3 k 3.0 Stores the k value.
  λ 3.672 Calculates the mean.


Poisson distribution - Wikipedia