What is the purpose of the 'Bessel's correction' in sample variance s2=1n−1∑(xi−xˉ)2s^2 = \frac{1}{n-1} \sum (x_i - \bar{x})^2s2=n−11∑(xi−xˉ)2?
To make the estimator unbiased
To increase the standard deviation
To account for population size
To simplify calculation