大全-B-19

19.   The U.S. census is not perfect: thousands of Americans probably go uncounted. However, the basic statistical portrait of the nation painted by the census is accurate. Certainly some of the poor go uncounted, particularly the homeless; but some of the rich go uncounted as well, because they are often abroad or traveling between one residence and another.

Which of the following is an assumption on which the argument above depends?

(A) Both the rich and the poor have personal and economic reasons to avoid being counted by the census.

(B) All Americans may reasonably be classified as either poor or rich.

(C) The percentage of poor Americans uncounted by the census is close to the percentage of rich Americans uncounted.

(D) The number of homeless Americans is approximately equal to the number of rich Americans.（C）

(E) The primary purpose of the census is to analyze the economic status of the American population.

How can the answer be C ?

The similar percentages of uncounted both rich and poor can justify the accuracy of census ? ridiculous to me.

My choice is  E.

If the census is aimed at collecting data on economic status, then the absence of either the poor or the rich will only present a distorted picture, right ?

Welcome to discussion .

This was ever disscussed, try "search".

Basicly, the rate is the matter not the exact number.

I know my explaination is weak.

Just put an example to make it clearer.

Imagine 3 people with salary 1, 2, 3 dollars respectively. The average is 2, right ?

But, the absence of either 1 or 3 will make the average to be 2.5 and 1.5, right ?

Only the simultaneous missing out of both 1 and 3 will keep the average still at 2 , thus counterbalance the absence , right ?

This is the same to the discussed question.

Welcome to further discussion.

But what's your answer's ground?

I believe "the basic statistical portrait of the nation painted by the census is accurate" is the argument, isn't it?

If it is, how could your answer be the assumption? learning from you.....

hehe, you are right in catching the arguement. Therefore , it would not be hard for you to see my point in following the thread of reasoning.

Just as my last example declares,  the avarage 2 is similar to a kind of economic status. Thus, the double ruling out of both poor and rich people will not effect the final calculation on people's average salary level.  So,  "the basic statistical portrait of the nation painted by the census is accurate" only if E "The primary purpose of the census is to analyze the economic status of the American population".

C is obvious wrong simply judged by common sense. The same percentage can show what ? The similar rate or the similar number ? Neither one will be able to offset the effect.  It is sort of like in a group of 100 , missing out one will cause the number smaller, but the missing out two will not. sounds ridiculous, right ?

my choice is also E, confusing now~~~

the same percentage of poor and rich who's not acounted dose not mean anything according to the argument"the basic statistical portrait of the nation painted by the census is accurate"

(E) The primary purpose of the census is to analyze the economic status of the American population.

E is unrelated.

19. The U.S. census is not perfect: thousands of Americans probably go uncounted. However, the basic statistical portrait of the nation painted by the census is accurate. Certainly some of the poor go uncounted, particularly the homeless; but some of the rich go uncounted as well, because they are often abroad or traveling between one residence and another.

Which of the following is an assumption on which the argument above depends?

(C) The percentage of poor Americans uncounted by the census is close to the percentage of rich Americans uncounted.

结论是：调查结果正确

可能造成调查结果不正确的主要因素就是有人没被算进去。文中提到两个组，穷人和富人，所以要让调查结果正确，平衡这两组的关系既可。C提供了很好的答案，没算进去的穷人=富人

(E) The primary purpose of the census is to analyze the economic status of the American population.

我觉得1完全就是个无关选项，即使不是经济状况调查，比如是某个产品的调查，童谣要注意这两个demographic group。所以是否经济状况调查，不能支持结论，也不是前提。（可能说得不太明白，logic这个东西，要靠悟！嗬嗬，多看看就有感觉了，就会清楚认识ets的丑恶嘴脸！）