select 
    USER_ID as USER,
    POINT as PT,
    
    -- 偏差値
    -- 四捨五入する 
    round(
        -- 個々の点数と平均値との差に10を掛ける
        (
            POINT - 
            (
                select avg(POINT) 
                from TEST_RESULTS 
                where TEST_ID = 100
            )
        ) * 10
        /
        -- 標準偏差
        -- 2乗
        sqrt(
            (
                select 
                    -- 合計する
                    sum(
                        -- 2乗する
                        pow(
                            -- 平均との差
                            (
                                (
                                    select avg(POINT) 
                                    from TEST_RESULTS 
                                    where TEST_ID = 100
                                )
                                - POINT
                            )
                        ,2)
                    )
                    /
                    (
                        select count(*)
                        from TEST_RESULTS 
                        where TEST_ID = 100
                    )
                    
                from TEST_RESULTS
                where TEST_ID = 100
            )
        )
         + 50
    ,1
    )
    as DEV_VAL
    
from TEST_RESULTS

where TEST_ID = 100

order by
DEV_VAL desc,
USER asc
;