n = Variance = ∑(x - x̅) n When the sample size is less than , variance = ; When n = number of observations. Example : Calculate the standard deviation from the following data by Actual Mean Method : , , , , , , , , and . Solution: Deviations from actual mean. Sl.
No Values (X) X – X̅ (X – X̅) - = - = - = - - = - = - = - =- - = - =- N= 𝜎 =