Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,604

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,354

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.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,501

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://www.thestudentroom.co.uk/showthread.php?t=908222

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

Bob

Children are not defined by school ...........The Fonz

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

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,604

Very interesting, thanks!

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

Offline