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### Binomial and Normal Distribution

```
Date: 06/09/99 at 03:52:52
From: Emma
Subject: Normal distribution

Could you please tell me the difference between normal approximation
to binomial distibution and normal distribution?
```

```
Date: 06/09/99 at 05:47:24
From: Doctor Mitteldorf
Subject: Re: Normal distribution

The binomial distribution is really a bar graph. It's the probability
of getting r heads when you flip a coin n times, and r is an integer
between 0 and n, so it's n+1 bars all together.

But as n gets bigger and you step back and look at the bar graph, it
looks smoother and smoother, with smaller and smaller bars closer and
closer together. It begins to take on the shape of a normal
distribution, which is a smooth, continuous curve. The normal
distribution it looks like has a particular mean and standard
deviation; those two numbers together completely describe any normal
distribution.

A normal distribution that is "fitted" in this way to be as close as
possible to a particular binomial distribution is called a "normal
approximation to the binomial distribution."

- Doctor Mitteldorf, The Math Forum
http://mathforum.org/dr.math/
```
Associated Topics:
High School Statistics

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