Normal approximation to the error distribution

If the sample size, n, is large enough, the binomial distribution is approximately normal, so we have the approximation

error  =  p − π  ~  normal (0, )

You will see later that it is often easier to use this normal approximation than the binomial distribution.


Closeness of the normal approximation

The following examples illustrate how the standard error is found and show the normal approximation to the error distribution.

Examples