calculating variance formula sum

To calculate the confidence interval for variance or standard deviation, a statistical distribution called ______ is needed. => chi-square distribution or binomial distribution or poisson distribution or multinomial distribution..

Molecular mass is equal to sum of the atomic masses of all atoms present in one molecule of the substance.Example: H 2 OMass of H atom = 1Mass of 2H atoms = 2Mass of O atom = 16Molecular mass = 2 + 16 = ..

Write down the formula of the given molecule/ion leaving some space between the atoms. Write oxidation number on the top of each atom with 'x' in case of the atom whose oxidation number has to be calculated. Write down the total oxidation numbers of each element beneath ..

Let, The mass of the organic compound taken be = W g Increase in the mass of magnesium perchlorate tube = W 1 g Increase in the mass of the KOH tube = W 2 g So, Mass of water formed = W 1 g Mass of carbon dioxide formed = W 2 g ..

Let, The mass of the organic compound be = W g Mass of the precipitate of BaSO 4 = W 1 g From stoichiometry, BaSO 4 = S 1 mol 1 mol 1 molecular mass 1 atomic mass 233 g 32 g Therefore, ..

Let, The mass of silver salt taken for ignition be = W g Mass of silver left behind after ignition = W 1 g We have RCOOAg = Ag1 equivalent 1 equivalent The equivalent mass of silver is 108. Hence, the mass of silver salt that would leave 108 g of residue (equivalent mass of the silver) i..

Let, The mass of the organic compound taken be = W g Volume of air displaced = V 1 mL Atmospheric pressure = P mm of Hg Room temperature, T 1 = t o C = (t + 273)K Aqueous tension at t o C = p mm of Hg Pressure of the dry air, P 1 = (P-p) mm Hg ..

Let, The mass of the organic compound taken be = W g Volume of nitrogen collected = V 1 g Atmospheric pressure = P mm Hg Temperature at which gas is collected = T 1 K Therefore, Pressure of the N 2 gas, P 1 = (P - p) mm of Hg ..

If X is a discrete random variable then variance of X denoted by V(X) is defined as V(X) = E [X - E(X)] 2 V(X) = E(X 2 ) - [E(X)] 2 ..

We have = n(n-1) p 2 (p+q) n - 2 + np = n 2 p 2 - np 2 + np = n 2 p 2 + np(1-p) = n 2 p 2 + npq Now V(x) = E(x 2 ) - [E(x)] 2 = n 2 p 2 + npq - n 2 p 2 = n..