统计学家对好友说的话

3Blue1Brown讲了一个故事。两个好朋友多年之后在咖啡馆中重聚，讨论各自的工作。其中一个成了统计学家，拿出最近的工作——人口统计——给另一位看。第一页写着高斯分布的公式。对于人的身高或体重符合这个公式，好友表示很惊讶。好友问统计学家，公式中的$\pi$是什么，她回答说，是圆的周长和直径的比值。好友更诧异了，你是在开玩笑吧，为什么人口统计和圆的周长比直径有关。

被这个故事触动到了某些回忆。只有很了解我的人知道我在说什么。

3B1B told a story. Two good friends in senior high school reunited in a coffee shop after many years. They were discussing their jobs. One of them became a statistician, and she showed her new work, population statistics, to her friend. Gauss distribution lay down in the first page. Her friend is very shocked that the height or the weight of the population follows this formula. She asked the statistician, “what is the $\pi$ in the formula?” “It is the ratio of a circle’s circumstance and its diameter” The latter one answered. The friend is even more astonished, “Are you kidding me? Why does population statistics have anything to do with the ratio of a circle’s circumstance and its diameter?”

This story recalls a memory deep down in my heart.