Normal and power law distributions

AI Thread Summary
Independent random events tend to produce a normal distribution when summed, while dependent random events lead to a power law distribution when multiplied. The discussion explores the creation of two sorted lists, S(i) and P(i), derived from the sums and products of random numbers, respectively. Observations indicate that as the number of random numbers increases, S(i) increasingly resembles a normal distribution, whereas P(i) aligns more closely with a power law distribution. The method involves using a spreadsheet to generate random numbers, calculate their sums and products, and analyze the frequency of the resulting values. This hypothesis highlights the relationship between the nature of random events and the resulting statistical distributions.
erszega
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Is it correct to say that independent random events (additively) lead to a normal distribution, and dependent random events (multiplicatively) lead to a power law distribution?

The following might be trivial, but it was quite interesting to find for me, someone with a very limited knowledge of mathematics or statistics:

Take a matrix of random numbers r(i,j), where 0 < r(i,j) < 1.

Let S(i) = int( ( r(i,1) + r(i,2) +...+ r(i,j) )*n ), with S(i) >= S(i-1) if i >= i-1, that is, S is a sorted list of the integer parts of the sums of random numbers multiplied by an integer.

Let P(i) = int( ( r(i,1) * r(i,2) * ... * r(i,j) )*n ), with P(i) >= P(i-1) if i >= i-1, that is P is a sorted list of the integer parts of the products of random numbers multiplied by an integer.

Hypothesis (based simply on observation of graphs of S(i) and P(i)):

the higher the values of i and j, the more S(i) approximates normal distribution, and P(i) approximates a power-law distribution.

Is this right?
 
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Apologies, I meant the frequency of each S(i) or P(i).
It may be better to describe what I did in the following way:
I used a spreadsheet, and created a table, consisting of, say, 10,000 rows and 5 columns, of random numbers (using the spreadsheet's random number function). Then I added (or multiplied) the random numbers in each row. I multiplied the sums (or products) by, say, 100, and took the integer parts (to create "bins"). Then I sorted the "bins", calculated the frequency (number of occurencies in the list) of each "bin", and then put a graph on the frequency list. I hope this makes sense.
 
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