Question

For which binomial distribution would a poisson approximation be acceptable? a. n = 60, π = 0.08

Answer 1

Generally, when n is large, say >=20, and p is small, say <0.05, it would be safe to approximate with a Poisson distribution.

However, the fact that np=4.8 <<10, and n=60 >>20 (I prefer working with 30), can justify approximating with Poisson.

So you see that when n is large, there is more tolerance.