Normal approximation to the
Poisson distribution 1
You can change some of
the details in the question and then see the solution, step by step.
Summary
Cumulative Poisson probabilities are available in table form
for values of l in the range 0.5
to 10. For larger values of l an
approximation has to be used. The Normal distribution provides a good
approximation to the Poisson distribution for
l > 10.