归纳题请教第一题！

Venus · 发表于 2004-1-15 02:17:00

A recent survey of all auto accident victims in Dole Country found that, of the severely injured drivers and the front-seat passengers, 80 percent were not wearing seat belt at the time of their accidents.This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.
The conclusion above is not properly drawn unless which of the following is ture?

A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.

这个正确答案的范围是20% in the survey，但提干中说80% of severely injured.2个比较范围不同，我不理解答案。
请指教

[此贴子已经被作者于2004-1-15 2:38:14编辑过]

番茄炒蛋 · 发表于 2004-1-15 23:30:00

这里用的是排除他因
如果那80percent的除了没有扣安全带还喝了很多酒呢，呵呵，那自然都是该死的，所以这里一定要说清楚那剩下的20percent是为什么没事
只有把一件事的正反面都说清楚了，这个逻辑才是完整的啊
多看两眼你就会习惯了吧

Venus · 发表于 2004-1-16 01:26:00

我的不解是说20和80 的比较范围不同，你在看看。
出处陈向东归纳30

must750 · 发表于 2004-1-16 03:41:00

In a club, 2 males & 8 females play basket ball

The club has totally 20 males & 70 females.
=> female is prone to play basket ball because (2/20)<(8/70)

The club has totally 20 males & 90 females.
=> male is prone to play basket ball because (2/20)>(8/90)

Same reason for the question.

寂寞的自由 · 发表于 2004-1-16 04:31:00

这个也是我遇到的一个疑问难点，请大家给予帮助

feizhou · 发表于 2004-1-16 06:18:00

唉~~
我也不明白了

up!

snow_mountain · 发表于 2004-1-16 10:04:00

of the severely injured drivers and the front-seat passengers, 80 percent were not wearing seat belt at the time of their accidents ——》说明有20％的人也是受了重伤，但是戴了安全带。

那么总体戴了安全带的人一定要超过20％，才能说明有人带来安全带，因而没有受伤。

mindfree · 发表于 2004-1-16 10:29:00

Agree with must750 and bryony.

If exactly 20% wear seatbelt, that means the injured is a perfect sample of the total population, for example:

out of total 100 people, 20 wear seatbelt; out of 10 injured, 2 wear seatbelt.

Then you can hardly conclude how seatbelt works and the conclusion in the argument does not hold.

番茄炒蛋 · 发表于 2004-1-16 13:42:00

嗯，是我看错了，功力还不够啊
应该是比例的问题，而不是我先前说的一件事情的正反两面
支持bryony

归纳题请教第一题！

归纳题请教第一题！

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