Normal Dist Confidence Intervals

is it enough to know the approximate intervals: 1std dev = 68% 2std dev= 95% 3 std dev =99% or will we also need to know the precise intervals: 1.65st dev = 90% 1.96std dev = 95% 2.56std dev = 99% …?


there wasn’t many questions on this topic in June but personallly I wouldn’t risk it

I hate this stuff.

when you look at the online CFAI exams though, they seem to be pretty sloppy with the std devs in the answer key. Like they’d use 2 rather than 1.96, etc. I personally don’t think that the correct choice on the exam will depend on whether you plug in 2 rather than 1.96, but you never know.