VAR_SAMP

1
SELECT VAR_SAMP(test_score) AS score_variance
2
FROM sample_students;

1
SELECT question_id,
2
       VAR_SAMP(rating) AS rating_variance
3
FROM survey_responses
4
GROUP BY question_id;

1
SELECT 
2
  AVG(value) AS mean,
3
  VAR_SAMP(value) AS variance,
4
  VAR_SAMP(value) / COUNT(*) AS variance_of_mean
5
FROM experiment_data;