Normal Approximations

Question 1

When do you approximate a Binomial with a Normal?

Answer 1

If X~B(n,p) and n is large and p is close to 0.5, then X can be approximated by Y~N(np,np(1-p))

Question 2

When do you approximate a Poisson with a Normal?

Answer 2

If X~Po(λ) and λ is large, then X can be approximated by Y~N(λ,√(λ)^2)

Question 3

What is the converter formula for Normal distribution?

Answer 3

Z = (x-µ)/σ