As a way to deal with trolls, here is a statistical breakdown of penis size in the United States.
First off, I would like to say that the mean (connotated as μ later on) is based off of the January 2015 study that established that the average penis length in the US was 5.17 inches long.
References:
https://www.medicalnewstoday.com/articles/271647.php
https://news.sciencemag.org/biology/2015/03/how-big-average-penis
https://www.cnn.com/2015/03/05/health/normal-penis-size/
That said, there are constantly questions on this site, and on the internet in general asking "I'm 15 and my penis is 500 inches long, is this normal?". And one thing that the study also published along with the average length, is the standard deviation, which is 0.8 inches. To explain this simply, Standard Deviation (later connotated as σ) is a number that states the distance a result is from the average.
Now, penis size on a bell curve has a mean (μ) of 5.17, and a Standard Deviation (σ) of 0.8. That means that the exact center average size of the penis in the US is 5.17 inches long, and 68% of ALL penises in the US will fall between 4.37 inches and 5.97 inches long. This is quickly notated as (μ ±σ), or 5.17 ±0.8.
When you look at this bell curve, you will see that the mean is directly in the center, and the farther you get from that center the smaller the amount of results in that category. The way this is broken down for penis size is exactly the same. 68% of all penises in the US will be within 0.8" of the average, 95% of penises will be within 1.6" of the average, and 99.7% of all penises will be within 2.4" from the average. To break this down further, we can say:
-68% of penises are between 4.37" and 5.97"
-95% of penises are between 3.57" and 6.77"
-99.7% of penises are between 2.77" and 7.57"
Now, what does this mean exactly? One, if you are within a single standard deviant of the mean, you fall within the "size doesn't matter" area because you aren't far enough from the average for it to really have an affect on anything. But more importantly, two: we can easily calculate the chance of the ridiculous internet claims actually being true.
Let's take the most common internet penis size claim, 8 inches, and look at the chance of that person not being full of shit. (8.0-5.17)=2.83, (2.83/0.8)=~3.5
- A penis being μ ± 3.5σ has a population range of 0.999534741841929. Which means that only 1 person in 2149 people will fall that far from the mean. Only one in 2149 men in the US have a penis of at least 8 inches.
Now, in case you're wondering where you fall in on this scale, or how likely someone making a ridiculous penis claim is to be lying, I have broken down a short list of sizes and a rough corresponding probability.
About 1 inch, σ=5.21, (μ - 5σ) ~1 in 1,744,278
About 2 inch, σ=3.96, (μ - 4σ) ~1 in 15,787
About 3 inch, σ=2.71, (μ - 3σ) ~1 in 370
About 4 inch, σ=1.46, (μ - 1.5σ) ~1 in 7
About 4.5 inch, σ=0.84, (μ - σ) ~1 in 3
About 5 inch, σ=0.21, (μ) ~2 in 3
About 5.5 inch, σ= 0.33, (μ+0.5σ) ~2 in 3
About 6 inch, σ=1.03, (μ + σ) ~1 in 3
About 6.5 inch, σ=1.66, (μ + 1.5σ) ~1 in 7
About 7 inch, σ=2.29, (μ + 2σ) ~1 in 22
About 7.5 inch, σ=2.91, (μ + 3σ) ~1 in 370
About 8 inch, σ=3.54, (μ + 3.5σ) ~1 in 2149
About 9 inch, σ=4.79, (μ + 4σ) ~1 in 15,787
About 10 inch, σ=6.04, (μ + 6σ) ~1 in 506,797,346
About 11 inch, σ=7.29, (μ + 7σ) ~1 in 390,682,215,445
I am going to stop there, as any further becomes pretty much incalculable. The world's largest penis, 13.5 inches long belonging to Jonah Falcon is almost 10.5σ from the mean, which is a deviation nearing impossibility.
According to these statistics, there MIGHT be one single man in the United States with a penis that is 10 inches long or more.
Probability of results taken using:(https://en.wikipedia.org/wiki/Standard_deviation#Rules_for_normally_distributed_data )
I understand that this is delving far more into this particular subject than is needed, but I did this as a way to show that with most of these claims on here, say 8 inches again as example, only have a 0.00047% chance of being true. And something as ridiculous as a 10 inch penis only has a chance of 0.000000002%.
Now, the average length per country does differ slightly, but for locations such as the US, UK, or Canada, these number are largely the same.
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