逻辑笔记中一道题的困惑

cjbbilly

这道题的样本是什么？为什么说B选项提到了样本，而E选项没有？根据统计枚举推理方法来做这个题，很难把握什么是真正的样本，有没有大神指点一下如何找样本啊？逻辑笔记里没有讲这个最关键的方法

另外我觉得这个题的样本是“在此次研究中的随机写有thank you的这些bill”，而B选项不符合这个要求，所以无法解释选择B选项的理由！

In a study conducted in Pennsylvania, servers in various restaurants wrote “Thank you” on randomly selected bills before presenting the bills to their customers.  Tips on these bills were an average of three percentage points higher than tips on bills without the message.  Therefore, if servers in Pennsylvania regularly wrote “Thank you” on restaurant bills, their average income from tips would be significantly higher than it otherwise would have been.

Which of the following is an assumption on which the argument relies?

A. The “Thank you” messages would have the same impact on regular patrons of a restaurant as they would on occasional patrons of the same restaurant.

B. Regularly seeing “Thank you” written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.

C. The written “Thank you” reminds restaurant patrons that tips constitute a significant part of the income of many food servers.

D. The rate at which people tip food servers in Pennsylvania does not vary with how expensive a restaurant is.

E. Virtually all patrons of the Pennsylvania restaurants in the study who were given a bill with “Thank you” written on it left a larger tip than they otherwise would have.

wwxavier

Random Thank You Bill -> Tips increase => Regular Thank You Bill -> Tips increase =>统计枚举题型
样本 Thank You Bill
在B,E之间选择，找样本与总体之间的关系
我觉得Helr老师对B选项的翻译有错误但后面的解释可以借鉴，B选项的意思是，经常看到Thank You的bill不会让食客改变回以前付小费的习惯。给了一个总体的概念，其实选项里regularly一出现就已经给了你一个总体。是CQ1.
我觉得楼主应该好好看看Helr老师对E选项的解释，说的非常清楚。E选项是说这个调查研究中（也就是这个样本里）所有的Pen. Patrons因为看到Thank You多付消费，并没有给总体的概念还是在说样本，所以E是错误的。
不知道我有没有解释清楚。

cjbbilly

wwxavier 发表于 2013-10-28 05:01
Random Thank You Bill -> Tips increase => Regular Thank You Bill -> Tips increase =>统计枚举题型
样 ...

多谢兄台的评论，其实我问这个问题的初衷是想讨论一下如何准确命中“样本”，样本顾名思义应该是指抽样调查的对象，样本的范围肯定是比较小的，我的理解是regular thank you bill已经超出了样本的范围，所以针对B选项，我看都不看就直接干掉了，因为这个方法论的前提是选项必须包含样本，但是如果找不出真正的样本的话，这种方法是很难用好的！哎~