Jan 7, 2025 · I also know that sample variance has the formula "Mean of the squares minus the mean squared". While calculating the sample variance of a given sample, I used both the formula and …

Feb 25, 2016 · If the sample variance is larger than there is a greater chance that it captures the true population variance. That is why when you divide by $ (n-1)$ we call that an unbiased sample estimate.

Aug 28, 2015 · The variance estimator makes use of the sample mean and as a consequence underestimates the true variance of the population. Dividing by n-1 instead of n corrects for that bias.

This formula works directly with the underlying sample means and sample variances of the two subgroups, and does not require intermediate calculation of the pooled sample mean.

In order to respond (offline) to a now-deleted challenge to the validity of this answer, I compared its results to direct calculation of the variance of the product in many simulations. It's not a practical …

Unbiased weighted variance was already addressed here and elsewhere but there still seems to be a surprising amount of confusion. There appears to be a consensus toward the formula presented in …

The formula for computing variance has (n−1) (n 1) in the denominator: s2 = ∑N =1(x−x¯)2 n−1 s 2 = ∑ = 1 N (x x) 2 n 1 I've always wondered why. However, reading and watching a few good videos about …

One reserved observation is "-1" and so you have N-1 in computing the variance estimate. The unbiased estimate is called sample variance (not to be confused with the sample's variance) which is an argot; …

Dec 17, 2021 · Could someone explain for me what the difference between Combined variance and pooled variance is? I have couple of groups (more than 2) with different sample size, I want to …

May 5, 2021 · Variance of product of multiple independent random variables Ask Question Asked 12 years, 9 months ago Modified 2 years, 3 months ago