The units of this quantity are found by squaring the units of the variable.
The Bienayme [byen-ae-may] formula states that two values of this quantity can be added to find the new value when two uncorrelated random variables are added or subtracted. In the central limit theorem, this variable is divided by the number of samples. This quantity is equal to the expected value of the quantity variable squared, end quantity, minus the expected value squared. In a Poisson [pwie-sone] distribution, this quantity equals the expected value. The units of this quantity are found by squaring the units of the variable. Name this measure of spread whose square root equals standard deviation.
The Bienayme [byen-ae-may] formula states that two values of this quantity can be added to find the new value when two uncorrelated random variables are added or subtracted.
(sample or population) variance