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The (statistical) Truth About Cock Size

Originally Posted by redskins2k9
Thanks a lot Priapologist.
To more accurately track my percentile growth, how can I convert standard deviation to percentile? I tried looking it up, but I don’t understand. They say I need a z table?

Take a look at this: http://math2.org/math/stat/distributions/z-dist.htm. Scroll to the bottom of the page. Input the following:

mean = 5.877
standard deviation = 0.825
right bound = your size

What you are doing is finding the area under the bell curve from -infinity to your size. This gives you your percentile.

Thanks for your contibutions gentlemen this makes very interesting and based on that which I have seen over the years seems quite accurate.


05/12/2005 : BPEL: 6.1"x EG:5.5" Current as of : 24/12/2011 : BPEL 7.87" x EG: 6.3" Long term Goal 8.5"x 6.4"

" There is only one option success; for failure is the refusal to persist"

Originally Posted by redskins2k9
Thanks a lot Priapologist.
To more accurately track my percentile growth, how can I convert standard deviation to percentile? I tried looking it up, but I don’t understand. They say I need a z table?

Yes, you will need a z-score table from a statistics book, or a z-score calculator - there are several on the web. The number of std dev that a number is from its mean is called the z-score. In your case:

Originally Posted by Priapologist
Length:
7.5 - 5.877 = 1.623 inches
1.623 / 0.825 = 1.967 standard deviations above the mean, which is the 97.54 percentile or 1 in 41.

Your z-score for length is 1.967, so you would find that on the table for positive z-scores, i.e. measures that fall above the mean, since yours do. You would look at the primary axis for 1.9, then follow the row over until you reach 0.07 on the secondary axis (because the 1.967 rounds to 1.97), which provides a score of 97.56, which is your percentile. Note that this percentile is slightly higher than the one that I quoted. This is due to the rounding up from 1.967 to 1.97.

The alternate method is to use a z-score calculator from the web, but there is a bit more work involved. Once you plug your “Given z” into the window and click on the Calculate button, you will be given a probability, Q, which will require conversion to a percentile. Use this formula for measures above the mean (see NOTE at page bottom for measures below the mean):

%ile = (-(Q)+1) * 100

In your case, it will look like this:

Q = 0.024592

Convert this to a negative number:

-0.024592

Add 1:

0.975408

Multiply by 100:

97.5408th percentile

This z-score calculator also gives probability as 1 in x, as you will notice.

Good luck on tracking your progress.

NOTE: for measures below the mean you can simply take the given probability, 0.024592 (for 1.967 std dev), and multiply by 100.

%ile = 0.024592 * 100 = 2.4592 percentile


Last edited by Priapologist : 04-28-2008 at .

Originally Posted by Invisible
Take a look at this: http://math2.org/math/stat/distributions/z-dist.htm. Scroll to the bottom of the page. Input the following:

mean = 5.877
standard deviation = 0.825
right bound = your size

What you are doing is finding the area under the bell curve from -infinity to your size. This gives you your percentile.

This method puts me in the 99.88 percentile. Definite ego boost


6 X 5(Jun 2002) ----> 8 7/8 X 6 (OCt 2009) -----> 9.75 X 6.0 (Goal)

'I think you will find that the one thing all big gainers have in common is tenacity.' ~Bib

Thanks a lot everyone. Great work and fast response.

Bros,
All you guys are real characters.
Who would of thought that you could come to a PE website and discover mathematical analysis unlike any you might expect from a bunch of guys who pull their cocks all day long.
the mean, linear regression, covariance, standard deviation, percentile, Z test, etc.

Only at Thunders men…only at Thunders.
You guys make me proud to be a member here. ;)


If you knew you could not fail...what would you attempt to do? Female Foot Fetish Current Stats: 5/4/10 8.5BPx6.0, 7.5NBP Achieved Goal and have been on maintenance program since

2006.

It sort of surprised me that length is correlated with girth. Hardly seems fair.

Originally Posted by supersizeit
Bros,
All you guys are real characters.
Who would of thought that you could come to a PE website and discover mathematical analysis unlike any you might expect from a bunch of guys who pull their cocks all day long.
the mean, linear regression, covariance, standard deviation, percentile, Z test, etc.

Only at Thunders men…only at Thunders.
You guys make me proud to be a member here. ;)

Now if only they had used these examples in my statistics course in college :)


6 X 5(Jun 2002) ----> 8 7/8 X 6 (OCt 2009) -----> 9.75 X 6.0 (Goal)

'I think you will find that the one thing all big gainers have in common is tenacity.' ~Bib

Originally Posted by beenthere
It sort of surprised me that length is correlated with girth. Hardly seems fair.

Think about it. One of the common denominators (I thing I read this on here) is the amount of testosterone you get in the womb & when puberty onsets has an influence on penis size. Now the higher levels of testosterone would likely increase the girth & the length.

Disclaimer, this could be completely offbase.


6 X 5(Jun 2002) ----> 8 7/8 X 6 (OCt 2009) -----> 9.75 X 6.0 (Goal)

'I think you will find that the one thing all big gainers have in common is tenacity.' ~Bib

My girth is not correlated to my length. I have always been somewhat of a pencil dick.


Liquid c :gulp:

Originally Posted by ManhattanXL

My girth is not correlated to my length. I have always been somewhat of a pencil dick.

4.5 is pencil dick?? I’d assume 4 to be pencil dick, 4 or less. I think 4.5 is decent, and above is best. I myself am 4.5.


`Start: 5"NBPEL, 6"BPEL, 4.5"EG

`Current: 5"NBPEL, 6"BPEL, 4.5"EG

So far a few fractions of inch increase on base erect girth.

Refresh, he probably meant his girth in relation to his (above average) length looks small.

Originally Posted by supersizeit
Bros,
All you guys are real characters.
Who would of thought that you could come to a PE website and discover mathematical analysis unlike any you might expect from a bunch of guys who pull their cocks all day long.
the mean, linear regression, covariance, standard deviation, percentile, Z test, etc.

Only at Thunders men…only at Thunders.
You guys make me proud to be a member here. ;)

Dang, Supe, you’re making me blush ;)

Originally Posted by ManhattanXL
My girth is not correlated to my length. I have always been somewhat of a pencil dick.

Sorry MXL, but your length and girth are still within two* standard deviations of each other, which does not qualify you to be a pencil dick. :)

*1.530 s.d. spread and 1.595 s.d. spread on your initial and most recent measurements, respectively.

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