I'm not going to expand on this because I can't get into-- This is not a course in probability theory but I'm hopeful that you can see the formula and you can apply it.

我不准备拓展这一部分,毕竟这节课不是概率论,但我希望你们能记住这个公式,并且学会应用

耶鲁公开课 - 金融市场课程节选