The difference in the formula of population and sample variance can be explained as:
Population variance is said to be the value of variance that is calculated from population data, whereas sample variance refers to the variance calculated from sample data. This is the reason why value of denominator in the formula for variance in case of sample data is ‘n-1’, while it is ‘n’ for population data. Hence, the result of both variance and standard deviation derived from sample data is larger than those found out from population data.