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## #1 2013-10-19 08:26:30

MathsIsFun

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### Mean, Median and Mode from Grouped Frequencies

Another new stats page: Mean, Median and Mode from Grouped Frequencies

All feedback welcome!

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

## #2 2013-10-19 11:01:26

bobbym

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### Re: Mean, Median and Mode from Grouped Frequencies

Hi;

That was a lot more than I knew about it. I will use the page for notes, thanks!

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #3 2013-10-19 21:28:49

bob bundy
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### Re: Mean, Median and Mode from Grouped Frequencies

hi MathsIsFun,

Another good page.  I'd not met those formulas for median and mode in grouped tables; I've always worked from a sketch of a cumulative frequency graph; so I derived my own.

For continuous data, taking the median as the (n+1)/2 th value I get

It doesn't make much difference and it's only an estimate anyway, but, for example, with the baby carrots example I get 172.0, compared with your 171.7.

I drew a cumulative frequency graph and found the median from that as 172.

I've done some 'googling' and both formulas came up.

eg.

http://math.stackexchange.com/questions … stribution

Bob

You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

## #4 2013-10-22 15:17:14

MathsIsFun

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### Re: Mean, Median and Mode from Grouped Frequencies

Very interesting, thanks!

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman