The length of a line segment?

好，几何学是怎么说的来着？

麻省理工公开课 - 计算机科学及编程导论课程节选

So, we should use that, but people in finance resist using that because it's a lower number and when you're advertising your return you want to make it look as big as possible.

所以我们应该用这个指标,但金融界反感使用几何平均,因为它比其他平均数都来得小,他们为自己的收益率做广告时,当然希望数字越大越好

耶鲁公开课 - 金融市场课程节选