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标题: 请教PREP-57和58.请NN帮忙！搜不到的啊 [打印本页]

作者: Isabel221 时间: 2007-8-29 10:48
标题: 请教PREP-57和58.请NN帮忙！搜不到的啊

57. (34655-!-item-!-188;#058&007580)

Roland: The alarming fact is that 90 percent of the people in this country now report that they know someone who is unemployed.

Sharon: But a normal, moderate level of unemployment is 5 percent, with 1 out of 20 workers unemployed. So at any given time if a person knows approximately 50 workers, 1 or more will very likely be unemployed.

Sharon's argument is structured to lead to which of the following as a conclusion?

(A) The fact that 90% of the people know someone who is unemployed is not an indication that unemployment is abnormally high.

(B) The current level of unemployment is not moderate.

(C) If at least 5% of workers are unemployed, the result of questioning a representative group of people cannot be the percentage Roland cites.

(D) It is unlikely that the people whose statements Roland cites are giving accurate reports.

(E) If an unemployment figure is given as a certain percent, the actual percentage of those without jobs is even higher.

这个题答案是A.我选D.

58. (34705-!-item-!-188;#058&007581)

Roland: The alarming fact is that 90 percent of the people in this country now report that they know someone who is unemployed.

Sharon's argument relies on the assumption that

(A) normal levels of unemployment are rarely exceeded

(B) unemployment is not normally concentrated in geographically isolated segments of the population

(D) Roland is not consciously distorting the statistics he presents

(E) knowledge that a personal acquaintance is unemployed generates more fear of losing one's job than does knowledge of unemployment statistics

答案是B。

没有思路。。。。两个题搞的我很晕。请NN解释一下！谢谢！

[此贴子已经被作者于2007-8-29 19:35:51编辑过]

作者: platobungee 时间: 2007-8-30 01:04

两个题目是一样的，我帮你讲个稍难点的吧，然后57题你自己做

Roland说：国内90%的人都说自己认识某个失业的人！值得警惕了！

Sharon: 这很正常啊，比如就拿一个正常的事业率5%来说，就意味着20个人里有一个是失业的。所以，如果一个人他认识大约50个工作的人，那非常可能其中就有1个或更多个失业的呀

在这里，其实Sharon的理论是根据概率论的基本原理来的，例如说如果全国人民中奖率是10%，那就等于说10个人有1个会中奖。但在这个结论里做了总体样本是平均分布的假设（通俗点来说是机会均等），也就是说，如果全国人民如果就浙江人民在中奖的话，你如果在上海，你认识的10个人里就不会有人会中奖。

B选项说：失业情况不会集中在地理孤立的某些地区人口上（你可以想象如果上海人民全失业了...）

58. (34705-!-item-!-188;#058&007581)

Roland: The alarming fact is that 90 percent of the people in this country now report that they know someone who is unemployed.

Sharon's argument relies on the assumption that

(A) normal levels of unemployment are rarely exceeded

(B) unemployment is not normally concentrated in geographically isolated segments of the population

(D) Roland is not consciously distorting the statistics he presents

(E) knowledge that a personal acquaintance is unemployed generates more fear of losing one's job than does knowledge of unemployment statistics

作者: Isabel221 时间: 2007-8-30 20:29

哦~原来是这样的！明白了，57题也想通了！谢谢LS!

作者: wgaggassi34 时间: 2007-10-23 11:15

58题,看到题目简直都摸不到头脑,

作者: smallmole 时间: 2009-7-27 20:45

作者: jasondream 时间: 2010-9-14 16:47
很感谢！
我自己就是琢磨不通第二个人说的是什么，阅读能力很重要！

作者: fuentefuente 时间: 2011-1-11 18:06
受益！这2个题也一直没搞明白！

作者: 白菜的白 时间: 2011-2-23 09:54
谢谢啦

作者: carinass 时间: 2011-4-17 11:51
这两个人说话到底是个什么关系呢？Roland说现在90%的人都有认识失业的人，Sharon说正常的失业率是5%。Sharon反驳Roland到底是怎么反驳的呢？一个是现在，一个是正常，两个有什么关系吗？请NN解释一下！谢谢！

作者: yychole 时间: 2011-7-4 21:57
我原来一直不理解的地方是，Sharon5%的失业率怎么会得出a person knows approximately 50 workers, one or more will very likely be unemployed.虽然50*5%=2.5 (one or more)也说得过去。但总觉得很绕，最直接的逻辑难道不该是20个人里面有一个unemployed吗？？

作者: dawnssing 时间: 2011-8-4 19:03

哈哈哈，我也觉得，这个概率确实有点问题吧。但是就题目的思路就是50个人里至少>=1个人失业，也可以是2个人失业嘛，不冲突的。虽然挺奇怪···

作者: ibruhim 时间: 2011-8-8 23:06

这两个人说话到底是个什么关系呢？Roland说现在90%的人都有认识失业的人，Sharon说正常的失业率是5%。Sharon反驳Roland到底是怎么反驳的呢？一个是现在，一个是正常，两个有什么关系吗？请NN解释一下！谢谢！

-- by 会员 carinass (2011/4/17 11:51:44)

我和Carinass尤同感，第一个人说的90%的人都认识有失业的人是指失业率是1/90？
我觉得R再说东，S再说西，正常的失业率是50%怎么就能说明90%的人认识失业人事一个可能正常的失业率呢？

作者: 瑾olivia 时间: 2012-10-13 11:02
R：值得警惕的事情是这个地区的90%的人现在报告他们知道谁在失业。（也就是说R认为：因为现在高达90%的人知道谁在失业，意味着失业率真是高到离谱了）

S：但是一个正常，中等水平的失业率是5%，也就是20个人里面有一个人没工作. 所以在任何一个时间里，如果一个人认识大概50个工人，那么一个或者更多的人就是应该没有工作啊. （S认为，90%的人知道谁在失业才不会表明失业率高到离谱咧，你看即使是在只有5%的人失业的情况下，也还是可以知道谁没有工作啊. 失业率不是太高的情况下，人们都可以知道身边有谁在失业，而且很可能是90%的人知道谁在失业，难道只有在失业率无比高的情况下，才有高达90%的人报告谁在失业吗？所以R童鞋你完败啦，因为90%的人知道谁在失业根本不足以表明失业率非常高啊，两者米有必然的等比联系啊.）

问，S的反驳可以引出一下哪个结论？

A．   90%的人知道谁在失业的数据不能表明失业率高到反常
B．   现在的失业水平不是缓和（平稳）的
C．   如果至少有5%的工人失业，那么质疑代表人群的结果就不能是R引述的百分比了
D．   R 引述的人没有给出正确的报告
E．   如果失业率是一个确定的百分比，那么真正的失业百分比会更加高

所以，A果断对

作者: 牛掰 时间: 2013-5-16 15:57

platobungee 发表于 2007-8-30 01:04
两个题目是一样的，我帮你讲个稍难点的吧，然后57题你自己做Roland说：国内90%的人都说自己认识某个失业的 ...

受教了，谢谢！

作者: bejamin1111 时间: 2013-7-12 21:35

platobungee 发表于 2007-8-30 01:04
两个题目是一样的，我帮你讲个稍难点的吧，然后57题你自己做Roland说：国内90%的人都说自己认识某个失业的 ...

nice!!!!!!!!!!!!

作者: Feelalive 时间: 2013-7-13 14:30
非常感谢

作者: 夏天的雨默 时间: 2013-7-15 17:54
这俩个题困扰我很久了，谢谢platobungee大侠和瑾大侠的解释，很清楚！

作者: st_chin 时间: 2014-5-31 20:20
我来解释一下两个人statement的关系：
roland认为：这个国家，如果90%的人都说自己认识的人中有人失业，（证明失业率很高），值得警惕。
sharon说: (你说的这个情况，不一定就说明失业率很高），拿正常的失业率来看，5%：如果通常情况下一个人认识50个有工作的人，那么5%的失业率计算，这50个人中一定有一个以上的人失业。（考虑到“这个国家中每个人都认识50个有工作的人”---这个假设是sharon自己提出的）即：这个国家每个人都会说“我认识失业的人”，即100%的人都会说我认识失业的人。所以你roland的说法（90%的人说自己认识失业的人）不能说明失业率高。

作者: st_chin 时间: 2014-5-31 20:24

yychole 发表于 2011-7-4 21:57
我原来一直不理解的地方是，Sharon5%的失业率怎么会得出a person knows approximately 50 workers, one or ...

这是sharon给出的一个假设。不是说，一个人一定就只认识50个worker。而是说，“那我们举个例子吧，如果现在一个人认识50个worker，那么按照5%的失业率来算，就有至少1个以上的人失业）

作者: bananaitis 时间: 2015-4-1 10:04
the assumption is about a normal disbtribution. think about a bell curve in statistics

作者: 主色调 时间: 2015-4-7 20:44

platobungee 发表于 2007-8-30 01:04
两个题目是一样的，我帮你讲个稍难点的吧，然后57题你自己做Roland说：国内90%的人都说自己认识某个失业的 ...

同意！

作者: dxfy3572 时间: 2015-5-19 20:18
贴一个RON的解释：

2nd question:

the correct answer to this problem should be (b).

* sharon cites a statistic that applies on a broad scale -- she's quoting an unemployment rate, which must apply over an extremely broad geographical area (probably nationwide).
* she then moves to a statement about individual people, assuming that the same percentages that apply on a nationwide basis must therefore apply to each individual.

if there are large variations in unemployment rates across different geographical areas, then this argument doesn't hold, since the number of unemployed people known by different individuals in different areas will vary wildly. therefore, sharon must assume that there are NO such large variations.

引用lawyer：DENIAL TEST：将选项取非，原文结论不成立，则为正确选项。
assumption不能以己之矛攻己之盾

作者: dxfy3572 时间: 2015-5-19 20:28
BEFORE looking at the answer choices, let's consider possible assumptions:

In this case, Sharon is assuming that all people know a sample population of workers that are equally likely to suffer 5% unemployment. If this were not the case, Sharon's conclusion crumbles.

As answer choice B is a restatement of the assumption I recognized, it is the best answer. However, I will use the negation test with choice B to ensure that I have not been careless.

Original b) unemployment is not normally concentrated in geographically isolated segments of populations

Negated b) unemployment IS normally concentrated in geographically isolated segments of population

If unemployment were concentrated in geographically isolated segments of populations, then randomly selected individuals would not have an equivalent chance（和上面RON的红色部分一个意思） of knowing an unemployed person. Instead, based on geographic factors, some individuals would be much more likely to know unemployed workers than would other individuals. In this case, Sharon's conclusion crumbles.

The correct answer is B.

ps. I would identify this as a "fill in the logic gap" assumption type. The unstated assumption helps explain how we get from the premises (5% unemployment, 90% people know someone unemployed) to the conclusion (a person who knows 50 workers will most likely know at least one unemployed worker)

作者: DeliciaAn 时间: 2015-7-2 11:30
顶一下2楼牛牛，太感谢了。

作者: Ivy1111111 时间: 2015-11-26 20:07
感谢呀

作者: 只求750 时间: 2016-3-9 12:16
sharon认为所有人都认识一群失业率大约为5%的人/朋友，这就是sharon的assumption. 答案B符合这一假设，失业率并不是集中在某个地域。如果B选项是 unemployment IS normally concentrated. 那么就不是所有人都认识一群失业率为5%的人群了。

作者: 杨杨杨要过gmat 时间: 2016-6-23 14:17
感谢分享

作者: 争取一次就过 时间: 2017-1-19 17:53
明白多了

作者: cindy222 时间: 2017-2-5 12:27
完全读不懂题

作者: liqing661 时间: 2017-3-24 10:43
感谢dxfy3572的分享！终于懂了

作者: 750狗狗狗 时间: 2017-10-11 22:55

dxfy3572 发表于 2015-5-19 20:28
BEFORE looking at the answer choices, let's consider possible assumptions:

In this case, Sharon is ...

同意！

作者: IrvingHan 时间: 2018-8-9 10:52
感谢！学习了！

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