帮忙确认一道cr jj答案，不记得是gwd里面哪里了

yinyincat

Background information:  This year, each film submitted to the Barbizon Film Festival was submitted in one of ten categories.  For each

category, there was a panel that decided which submitted films to accept.
Fact 1:  Within each category, the rate of acceptance for domestic films was the same as that for foreign films.
Fact 2:  The overall rate of acceptance of domestic films was significantly higher than that of foreign films.
In light of the background information, which of the following, if true, can account for fact 1 and fact 2 both being true of the submissions to this year’s Barbizon Film Festival?
   1. In each category, the selection panel was composed of filmmakers, and some selection panels included no foreign filmmakers.
   2. Significantly more domestic films than foreign films were submitted to the festival.
   3. In each of the past three years, the overall acceptance rate was higher for foreign than for domestic films, an outcome that had upset some domestic filmmakers.
   4. The number of films to be selected in each category was predetermined, but in no category was it required that the acceptance rate of foreign films should equal that of domestic films.
   5. Most foreign films, unlike most domestic films, were submitted in categories with high prestige, but with correspondingly low rates of acceptance.

Rayakawr

e

yinyincat

谢谢，但是为什么选e?这道题是什么意思亚

raikey

这是TTGWD30的第14题,今天又错了一遍,算是记牢了.

题目是这个意思:有10种类型film,每种里有domestic和foreign两种film,并且每一种类型的film里,D和F的中签率相等. 然而结果总的中签率不一样.问如何解释这个"矛盾".

纯粹一个数学题目.
设第一种film中,提交了D1个Domestic film,其中有d1个中签; 同时提交了F1个Foreign film,其中有f1个中签.
  第二种film中,......D2......................d2..................F2.....................f2.......
                                     ...... ......
  第十种film中,......D10.....................d10.................F10....................f10
于是有这样的关系:
dn/Dn = fn/Fn 其中n∈{1,2,3,4,5,6,7,8,9,10}
且 (d1+d2+...+d10)/(D1+D2+...+D10) > (f1+f2+...+f10)/(F1+F2+...+F10)
再回过来看选项,ACD明显无关,就看B和E.
B说D1+D2+...+D10比F1+F2+...+F10要大很多,这关系不大,因为是两个比值比较,光知道分母大没什么用.
E说F集中在中签率很低的种类里.举个例子: F1相对于其他9个F值来说是"+∞",而f1/F1相对于其他9个f/F值来说无穷小,这意味着(f1+f2+...+f10)/(F1+F2+...+F10)约等于f1/F1,结果值就很小.

这到题告诉我们这样一个数学关系:
如果dn/Dn=fn/Fn,那么未必有∑dn/∑Dn=∑fn/∑Fn

yinyincat

谢谢指教，gg真牛啊

可是e的意思是说f集中在中签率很低的种类里？然而题目意思不是说每个种类里都有foreign films吗？with high prestige 是什么意思？帮忙翻译一下e的意思

raikey

Most foreign films, unlike most domestic films, were submitted in categories with high prestige, but with correspondingly low rates of acceptance

翻译:大多数外国片子,与国内片子不同,是在(十种片子中的)某几种非常受欢迎的(片子)种类里提交的,然而这几个片子种类的入选率非常低.

举个极端例子:十种类型中有一种含10000个Foreign和100个Domestic,入选率都是1%,而其他的9个种类里,每一种都有100个F和1200个D,入选率都是50%.
结果F总数有10900个,D总数也有10900个,入选的f数为10000*1%+9*100*50%=550,入选的d数为100*1%+9*1200*50%=5401
很明显550/10900 < 5401/10900

所以,即使F和D片子数一样多,总的入选率大小要视数据分布密度而定.