Population Samples: The Variance
There is one notable change in the equation for the variance: one is subtracted from the sample size n in the denominator. The Standard Deviation of the sample is the square root of the sample variance and is represented by s.
Case Example: The s2 of our Stanford population
What is the Variance and Standard Deviation of our Sample?
The Variance (s2) is 17.13; the Standard Deviation (s) is 4.1
A descriptive statistic particular to population samples is the Standard Error of the Mean, a term you will become more familiar with when discussing the Central Limit Theorem.