OG12-87,

winny莹

87。in the United States, of the people who moved from one state to another when they retired, the percentage who retired to Florida has decrease by three percentage points over the past ten years. Since many local businesses in Florida cater to retirees, these declines are likely to have a noticeable negative economic effect on these businesses and therefore on the economy of Florida.
which of the following, if true, most seriously weaken the argument above?
A. People who moved from one state to another when they retired moved a greater distance, on average, last year than such people did ten years ago
B.People were more likely to retire to North Carolina from another state last year than people were ten years ago
C.The numbers of people who moved from one state to another when they retired has increased significantly over the past ten years
D.The number of people who left Florida when they retired to live in another state was greater last year than it was ten years ago.
E.Florida attracts more people who move from one state to another when they retire than does any other state.
答案选C。
这题是不是说退休以后搬去佛罗里达州的人变少，对其经济造成不好的影响。还是说在佛罗里达州退休的人少啊？

cdbgin009

终于搞明白了。C中，因为总体退休移居的人数增长了很多，所以可以推测出即使去F的比例下降了，实际上去F得人的绝对数量“有可能上升，不变，或者下降”。 比例=去F得人数/总体退休移居的人数。分母增加，比值下降，则分子有可能上升，不变，或者下降。即C表示即使去F得比例下降了，但是由于总人数是上升的，去F的人数是可能增加或者不变的，所以可能对F的经济不会造成负面影响，这就否定了题目的结论，3%的下降对F的经济可能造成负面影响。请注意“可能”。而E，说F比其他地方吸引人，是什么都推测不出来了。E只能说明F的人数比其他地方的人数多，但是去F的人的数量本身是增加，减少，还是不变是不知道了。实际上，去F的人数只有三种情况，要么增加，要么不变，要么减少。C提供了一种很好的解释，说明即使比率下降，去F的人数还是有可能上升的。而E选项你推测不出来有任何上升或者不变的可能性的，即推测不出来在比率下降的时候去F的人数有上升的可能。

sdcar2010

percentage and number.

jiaying52

多谢6.7楼两位。7楼说选C选项的原因我是可以理解的，6楼讲的也有道理。
这道题目可以用引入他因吗？是不是只有因果类型题目才能引人他因呢？
读几遍感觉像条件类型....

涩姬

题干： the percentage who retired to Florida has decrease by three percentage points over the past ten years.   THE IMPORTANCE IS : THE PERCENTAGE

PERCENTAGE does not means THE NUMBER

C.The numbers of people who moved from one state to another when they retired has increased significantly over the past ten years

if the total number increased considerably, even though the percentage decreased, the number of Florida would increase as well....



REMEMBER:  ERCENTAGE   NOT EQUAL TO  THE NUMBER !!!!!

guojinxin

D选项是The number of people who left Florida when they retired to live in another state was greater last year than it was ten years ago.讲的是last year than it was ten years ago.而比较对象中的last year是无关选项。。。

jiaying52

去F的退休老人数下降3%--->影响靠退休人吃饭的企业--->影响F经济

-- by 会员 huangyouhuifei (2011/2/27 23:50:45)

D选项说去年，退休离开flordia去其他地方生活的人数比十年前大大增加。我觉得是引入另外一个原因，破坏原逻辑链上因为去flordia的退休人数下降引起的经济衰退。
所以我选D不知道为什么不对，求教！

Lacus

F的经济主要靠退休的客户，而C说退休的客户增加，自然就可以驳斥前面“经济衰退”的结论了。

huangyouhuifei

去F的退休老人数下降3%--->影响靠退休人吃饭的企业--->影响F经济

魏小妞要出国

比例下降，但是基数增加，最后的人数还是增加的
注意绝对数和相对数