with A as (
    select avg(POINT) as AVG from TEST_RESULTS where TEST_ID = '100'
) 
, B as (
    select 
        SQRT ( 
            AVG (
                  ( point - A.AVG )  * ( point - A.AVG ) 
            )
        ) as HEN
        from TEST_RESULTS cross join A  
        where TEST_ID = '100'
)
select 
    USER_ID as USER
    ,POINT as PT
    , case when HEN = 0 then 50
        else round ( ( ( (point - A.AVG) * 10 ) / HEN ) , 1 ) + 50
        end
      as DEV_VAL
from TEST_RESULTS
cross join A
cross join B
where TEST_ID = '100'
order by DEV_VAL desc , USER asc