# Normal distribution properties
To access the normal distribution properties, open "descriptive statistics/details"

![Propriétés loi normale](baseUrl/statsDescriptives/Proprietes-loi-normale.png)


In addition to “the universality” of normal distribution, it is also very practical to characterize. The normal distribution equation is:

![equation](f(x)=1/(2*pi)*e^((x-mu)^2/sigma^2))



Only two parameters completely characterizing the distribution:
- average
- standard deviation

If these two parameters are known, then all the characteristics of the observed distribution are fully known. 
This is what a normal distribution looks like with an average of 0 and standard deviation of 1:

![Loi normale1](baseUrl/statsDescriptives/Loi-normale1.jpg)


From now on the normal distribution average and standard deviation will be noted.  This distribution can be perfectly defined since the two parameters are known: average and standard deviation.

To understand the normal distribution well it is good to know the following figures:

- 68.27% of the actual values are located at + 1 of the average
- 95.45% of the actual values are located at + 2 of the average
- 99.73% of the actual values are located at + 3 of the average

![Loi normale2](baseUrl/statsDescriptives/Loi-normale-2.png)


Guida utente

Normal distribution properties

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