There is an example on the normal approximation for binomial distribution.

Given n =10, p = 0.2.

We calculate binomial distribution from k=0 to k=6.

... and so on.

The normal approximation is given as:

...... and so on.

Ok, I've been trying to figure out how to arrive at normal approximations given above, but to no avail.

Do I use:

where h=

For example,

which is different from the answer given.

I thank you for your comments. This is a particularly vexing problem, as I want to thoroughly understand the inner workigs of Normal Approximations.