standard Deviation(x)=[1/(n-1)[E(x^2)-E^2(x)]]^(1/2) standard Deviation(x)=[1/n[E(x^2)-E^2(x)]]^(1/2) Which one is to accept and at what ground? [Here E represents Summation]
The notation you use is a bit confusing but the final term on the top of the expression should be n x (xbar)^2, where xbar is the sample mean. When calculating the sample variance (s^2) we divide by n-1 so that it is an unbiased estimate of the population variance.
