with t as (
    select *
    from TEST_RESULTS
    where TEST_ID='100'
), u as (
    select sqrt(sum((POINT - (select avg(point) from t)) * (POINT - (select avg(point) from t))) / (select count(*) from t)) as z
    from t
)
select USER_ID as USER, POINT as PT, round(case when z = 0 then 50.0 else 50.0 + (POINT - (select avg(point) from t)) * 10.0 / z end, 1) as DEV_VAL
from t cross join u
order by 3 desc, 1