What is your purpose or goal?
What is your purpose or goal?
Stop cowardice, ban guns!
spunky (02-19-2017)
user1234 (03-10-2017)
The purpose is to talk about what Hillary and Roger are talking about after about 40 minutes.
https://soundcloud.com/nssd-podcast/...w-times#t=0:00
The sample variance is unbiased but the sample standard deviation in not unbiased and I find that so strange. Also, as they discuss: the bias and variance trade off.
Well, it's really not strange. In short, taking the square root of the variance is a non-linear transformation.
That said, if we assume that the population is normally distributed, then an unbiased estimate of the standard deviation (s) of the population standard deviation (Sigma) is as follows:
E[s] = [ (4*n - 4) / (4n - 3 ] * Sigma.
Thus, we have:
E { [ 1 + 1 / (4*(n - 1)) ] * s } = Sigma
GretaGarbo (02-20-2017)
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