程序代码：

* VFP9代码
CLOSE DATABASES ALL 
cStr="班级,总分,语文,数学,英语,物理,化学,生物,历史,地理,政治"
=ALINES(azd,cStr,",")
LIST MEMORY LIKE azd
cField="班级 C(2),总分 N(7,2)"
FOR i=3 TO ALEN(azd,1)
    cField=cField+","+azd[i]+" N(6,2)"
ENDFOR
SELECT distinct 班级 FROM 学校 INTO ARRAY abj
CREATE CURSOR 平均分 (&cfield)
APPEND FROM ARRAY ABJ
INDEX ON 班级 TO px
FOR i=2 TO ALEN(azd,1)
    SELECT 班级,AVG(&azd[i]) AS cj FROM 学校 GROUP BY 1 INTO CURSOR qb
    SET RELATION TO 班级 INTO 平均分
    SELECT qb
    SCAN 
        REPLACE (azd[i]) WITH qb.cj IN 平均分
    ENDSCAN 
    SELECT 班级,&azd[i] as cj FROM 学校 xx WHERE 20>(SELECT COUNT(*) FROM 学校 WHERE 班级=xx.班级 AND &azd[i] > xx.&azd[i] ) ORDER BY 班级,2 DESC INTO CURSOR q20

    SELECT 班级,AVG(cj) AS cj FROM q20 GROUP BY 1 INTO CURSOR q20
    SET RELATION TO 班级 INTO 平均分
    SCAN 
        REPLACE (azd[i]) WITH EVALUATE(azd[i])*0.6+q20.cj*0.4 IN 平均分
    ENDSCAN 
ENDFOR 
SET RELATION TO 
SELECT 平均分
SET INDEX TO 
BROWSE 
CLOSE DATABASES ALL 
ERASE px.idx