A Mathematical Proof for the Wisdom of Crowds. Re: Economic Basics Part 3: The Wisdom of Crowds.m4v

I found a few videos explaining what the Wisdom of Crowds is, but I had not found one which explains WHY it works, so I thought I would do so here.
For an explanation of what the wisdom of crowds is, see this video: http://www.youtube.com/watch?v=gKd_yG8DrkE

Category:

Education

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• wisdom
• of
• the
• crowds
• math
• maths
• mathematics
• linear
• combination
• sir
• francis
• galton

[Cromwell523]

so you mean several distributions of x each with a different mean? i.e. n sample groups with n samples each?

[enthalpay]

@Cromwell523 Just a single sample of size n. I make a lot of semantic errors in this video actually, I was concentrating on getting the math right and so the quality of the English deteriorated.

[Cromwell523]

What do you mean by variance of the mean? with a given number of X_i you only have one mean which is Sum(X_i/n). so it cannot have a varience.

Even in your example it should be obvious that you won´t get the right number of jellybeans within the jar just by asking an infinite number of people and i can prove that with a simple mind experiment if you are interested

[enthalpay]

@Cromwell523 I meant variance of the sampling distribution of the sample mean.

[shanedk]

Nicely done! Thanks.

[enthalpay]

@shanedk You're welcome!

[supergreatsuper]

@Cromwell523 I'm interested, but don't message me because I don't check my inbox that often, try responding to this comment

[donttreadonmyass]

Congratulations sir, you win the award for longest video title!!!