！sos！GWD-17-35

yangping

In a recent election, Ms. Robbins received 8,000 votes cast by independent voters, that is, voters not registered with a specific political party.  She also received 10 percent of the votes cast by those voters registered with a political party.  If N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters, which of the following represents the number of votes that Ms. Robbins received?

A.     0.06N + 3,200

B.     0.1N + 7,200

C.     0.4N + 7,200

D.     0.1N + 8,000

E.      0.06N + 8,000

Can you tell me how to do this question?

My answer is 0.6N +8000,Clearly,it is incorret,

perhaps ,i can not understand clearly the relation involved in it.so please help !i will appreciate you!

[此贴子已经被作者于2005-12-27 11:07:58编辑过]

赫连勃勃

以下是引用yangping在2005-12-27 11:02:00的发言：

In a recent election, Ms. Robbins received 8,000 votes cast by independent voters, that is, voters not registered with a specific political party.  She also received 10 percent of the votes cast by those voters registered with a political party.  If N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters, which of the following represents the number of votes that Ms. Robbins received?

A.     0.06N + 3,200

B.     0.1N + 7,200

C.     0.4N + 7,200

D.     0.1N + 8,000

E.      0.06N + 8,000

can you tell me how to do this question?perhaps ,i can not understand clearly the relation involved in it.

我猜是E

投票人有两种A自由选民B注册为某党支持者的选民

Ms. Robbins 拿到 A中的 8000票，B中的10%。 B = N(总票数)*（1-40%）（If N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters）

tomasy

答案是E吗? (1-0.4N)=0.6N*10% =0.06N 再加上8000

顺便问一下, GWD 17-19 & 21 的题目在哪里下载?

yangping

以下是引用赫连勃勃在2005-12-27 11:07:00的发言：

我猜是E

投票人有两种A自由选民B注册为某党支持者的选民

Ms. Robbins 拿到 A中的 8000票，B中的10%。 B = N(总票数)*（1-40%）（If N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters）

非常感谢：）你给我标的位置就是我没读明白的地方，我一直都主观地认为N是MS R 所得票的总数，这回我明白了，N实际上是投票总体的数，而非投给MS 的总票数。

yangping

以下是引用tomasy在2005-12-27 11:11:00的发言：

答案是E吗? (1-0.4N)=0.6N*10% =0.06N 再加上8000

顺便问一下, GWD 17-19 & 21 的题目在哪里下载?

http://forum.chasedream.com/dispbbs.asp?boardid=34&id=141074

谢谢，你看看这个，我就是从这位朋友那得到的。

christlulu

哈明白了。。。

dormousedzc

这道题目我觉得出得不太好,因为N明显是可以算出来的吧:N=8000/40%=20000

所以总数0.06N + 8,000 = 20000*(1-40%)+8000=9200

0.06N + 8,000搞得我心理好寒,还以为N是一个变数,以为关系没有理清,选E.的时候都是战战兢兢的.靠!!!

[此贴子已经被作者于2008-1-18 17:12:58编辑过]

BBBQQQ

选E没错！

但是楼上的推理好像有点问题。

8000说的是自由选民中投给Ms R.票的人数。

条件中又说40%的投票者是自由选民。这里所讲的投票者并非只投票给Ms R.的人啊！

从概率上讲，有可能，投给Ms R.的人中40%是自由选民，但是这种分布并不是一定的。不能说所有选民中40%的是自由选民，投票给Ms R.的人中就有40%是自由选民啊！这是其一，错在对样本分布的不合理推测。

即使我们不推敲样本分布的问题，8000/40%充其量也就只能算是投票给Ms R.的总人数（这是让步从句哈！这样子算是不对滴！）跟N相去甚远啊！这是其二，错在对样本大小的使用。

欢迎大家讨论！