It's all about the bias of the estimator.
Then is biased estimator of
In other words, (The expected value is actually .)
, on the other hand, is an unbiased estimator of because
I am very new to statistcs and just started learning it.
The concept of SD is defined in two ways - separately for the whole i.e. population and the sample thereof. In first case the square sum of variance from mean is divided by "n" i.e. total number of variables, but the second case is slighty different since it propose such division by "n-1".
What is the actual significance of this difference? Yes the concept of degree
of freedom is there to explain it,i as a newcomer i feel it little bit unintelligible.
Is there any simpler approach or analogy to grasp the pith of the concept?
My simple query is what if the dividor is "n" in both the case? What, otherwise, adverse bearing will be on the result?