And, yes the other point estimator is a sample variance with n=2.
So, the ratio is n-1 or 1/(n-1) depending on which way you divide.
Q) is a random sample from a normal distribution with mean and variance . Two unbiased estimators of are
Find the efficiency of relative to .
I am stuck on finding the proper variance for , . My work indicates , because is simply
with . Moreover, .
So, the efficiency of relative to is .
The book's answer is .
I am stuck, so any help would be great.