How is the normal distribution formula derived?

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The normal distribution formula is derived through the application of the standard deviation definition and the Central Limit Theorem, which demonstrates that binomial distributions approximate the normal distribution as the number of trials increases. This approximation shows that the error in using the normal distribution decreases to zero as sample size grows. Any function from R to R with an integral of 1 can define a probability distribution, but normal distributions are particularly prevalent in real-life phenomena. Understanding these concepts can clarify the derivation and application of the normal distribution. Exploring histograms of binomial distributions can further illustrate this relationship.
bomba923
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How do you derive the normal distribution formula??

How was it derived?

(mu=population mean,
sigma=std. deviation)

(see below thumbnail for formula)
 

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Have you attempted it?

I don't remember it off by heart but I do remember the proof on the board being quite simple once you apply the definition of S.D
 
To view the question slightly differently, have you plotted histograms of binomial distributions for a large number of trials? It approximates the normal distribution, ie the graphs agree, and it can be shown that as n goes to infinity that the exponential formula is "correct" (ie the error in using it goes to zero.

Note that ANY function from R to R whose integral over R is 1 defines a probability distribution, it is up to us to find real life situations for when to use them. It so happens that normal distributions appear to describe many real life phenomena.

Look up the Central Limit Theorem to see why it's so powerful.
 
matt grime said:
To view the question slightly differently, have you plotted histograms of binomial distributions for a large number of trials? It approximates the normal distribution, ie the graphs agree, and it can be shown that as n goes to infinity that the exponential formula is "correct" (ie the error in using it goes to zero.

Good idea-i'll try just that :smile:
 
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