Excel 2010 Statistics #30: Standard Deviation: How fairly does the mean represent its data points?

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1. Variability
2. Calculate Range
3. Calculate Interquartile Range
4. Calculate Sample Variance and Standard Deviation long hand
5. Calculate Sample Variance and Standard Deviation using VAR.S and STDEV.S
6. Coefficient of Variation
7. Build Chart to see variation in data

[@excelisfun]

I am glad that the videos help! Thanks for watching.

[@Aubury.Spartacus-Jones]

Thank you Mike,
The light is just beginning to dawn for me with Standard Deviation. Explaining it, as you have, is very helpful.

[@excelisfun]

That is awesome! SD is so important, and yet so few know what it means. Especially many of the investment bankers and CEOs that drove the world economy into the ground before during and after the financial crisis.
I am glad that the videos help!

[@udaydon4u]

You deserve Nobel Prize in Excel .. thanks a lot !

[@excelisfun]

I am glad that you like the videos!!

[@cosmosgato]

One of the best of the best dissuasion standard deviation I've seen.

[@excelisfun]

I am glad that you like them!

[@excelisfun]

I see the error now. I added an annotation at 13:22. Thanks so much for the help!!!

[@excelisfun]

Not totally meaning less, but it REALLY helps to have something to compare to.

[@excelisfun]

Cool! I am glad that you like it!

[@excelisfun]

Thank you very much! If you break Standard Deviation down it is quite easy:
1) Look at it on a chart to "see" it
2) Think of it as just an "average" of all the deviations
3) Think of it as "how clustered are the data points around the mean" or "How fairly does the mean represent its data points"
Just out of curiosity, cosmosgato, are you currently a student or a working at a job? And if you are working, do you use Standard Deviation in your work?

[@voodooman08]

we take (n-1) in sample statistics not just to make it more accurate, but also that way our estimates are not biased. It can be proved in formal way.

[@burnetterandall]

Mike your work is outstanding....

[@cosmosgato]

@ExcelIsFun I'm a forex trader. I use statistics to analyze my trade history. Is this setup working. Has the market shifted. At what point can you determine the difference between a good system having a string of bad luck and a really bad system. I majored in mathematics BUT DON'T KNOW EXCEL. Your videos have helped me greatly.

[@ekta9197]

hi, you are very nice guy! because of you I have understood the whole concept of finance. and now statistics. you are a great help to me. May Allah bless you with all you desire! I want to see you :) why dont you upload a small video :) ......thank you in tons and lots of love from India

[@excelisfun]

I am glad that the Finance and Statistics Video Classes help you! : )

[@maximpiras]

Hi Mike, have a look between min 13 - 13.30: you mention the pop. standard deviation whose symbol is sigma not sigma squared

[@jnscollier]

I never understood WHY we squared the deviations from the mean, then at the end took the square root. It's basically just to undo the squared deviations it sounds like. I still don't quite understand what the variance means though since it's a sum of squared deviations divided by n-1 (for sample). Isn't variance meaningless if you have nothing to compare it to?

[@yatwat3aeg2002]

would you mind tell how to get the excel file within the video

[@excelisfun]

people.highline.edu/mgirvin/excelisfun.htm

[@zachlebo]

Another fantastic vid!! Do you have any sample data that we can download by any chance?