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**tina123****Member**- Registered: 2012-04-29
- Posts: 83

How can we define histogram mathematically?

I need to define histogram in form of Equation. Can anyone please help me to do it,.

thanks

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,462

hi Tina123

If you have numeric data collected over varying range sizes, (eg. Number of calls to a switch board lasting 0-1min ; 1-2min ; 2-5min ; 5-10min etc) it would be misleading to use a bar chart because there would be a bias towards the larger ranges.

So a new frequency, called the relative frequency (or frequency density), is defined to unbias the figures:

Thus the area of each histogram bar is proportional to the recorded frequencies.

The histogram below shows varying range sizes rather well.

It comes from:

http://www.bbc.co.uk/schools/gcsebitesi … rev3.shtml

If it would help I will make up another example to show the correct use of a histogram.

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

Sometimes I deliberately make mistakes, just to test you! …………….Bob Bundy

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**tina123****Member**- Registered: 2012-04-29
- Posts: 83

Yes, I understand this .. thanks Bob..

bob bundy wrote:

hi Tina123

If you have numeric data collected over varying range sizes, (eg. Number of calls to a switch board lasting 0-1min ; 1-2min ; 2-5min ; 5-10min etc) it would be misleading to use a bar chart because there would be a bias towards the larger ranges.

So a new frequency, called the relative frequency (or frequency density), is defined to unbias the figures:

Thus the area of each histogram bar is proportional to the recorded frequencies.

The histogram below shows varying range sizes rather well.

It comes from:

http://www.bbc.co.uk/schools/gcsebitesi … rev3.shtml

If it would help I will make up another example to show the correct use of a histogram.

Bob

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