SELECT USER_ID AS USER
      ,POINT AS PT
      ,(POINT - (SELECT AVG(POINT) AS a
                  FROM TEST_RESULTS
                 WHERE TEST_ID = '100')) * 10
       / (SELECT SQRT(AVG(POW((TEST_RESULTS.POINT - sub.a), 2))) AS var
          FROM TEST_RESULTS 
              ,(SELECT AVG(POINT) AS a
                  FROM TEST_RESULTS
                 WHERE TEST_ID = '100') AS sub
         WHERE TEST_ID = '100'
       ) + 50 AS DEV_VAL
  FROM TEST_RESULTS
 WHERE TEST_ID = '100'
 ORDER BY DEV_VAL DESC
         ,USER_ID