It is ubiquitous in nature و statistics due to the مبرهنة النهاية المركزية: كل متغير that can be modelled as a sum of many small independent، identically distributed متغيرات with منتهية متوسط و تباين بشكل تقريبي طبيعي.
It is ubiquitous in nature and statistics due to the central limit theorem: every variable that can be modelled as a sum of many small independent, identically distributed variables with finite mean and variance is approximately normal.