WITH POINT_AVERAGE AS (
    SELECT SUM(POINT * 1.00) / (SELECT COUNT(*) FROM TEST_RESULTS WHERE TEST_ID = '100') AS AVE_PT FROM TEST_RESULTS WHERE TEST_ID = '100'
),
POINT_STDEV AS (
    SELECT SQRT(SUM((1.00 * POINT - AVE_PT) * (1.00 * POINT - AVE_PT)) / (SELECT COUNT(*) FROM TEST_RESULTS WHERE TEST_ID = '100')) AS STDEV_PT FROM TEST_RESULTS, POINT_AVERAGE WHERE TEST_ID = '100'
)
SELECT
     USER_ID        AS USER
    ,POINT          AS PT
    ,ROUND((((1.00 * POINT - AVE_PT) * 10.00) / STDEV_PT) + 50, 1) AS DEV_VAL
FROM TEST_RESULTS
    ,POINT_STDEV
    ,POINT_AVERAGE
WHERE TEST_ID = '100'
ORDER BY DEV_VAL DESC, USER
;