求助~~~对于CR费费94、125题的详解，现在仍然有疑问

张茹ava

对于CR费费94、125题的详解，现在仍然不太明白
94。When 100 people who have not used cocaine are tested for cocaine use, on average only 5 will test positive. By contrast, of every 100 people who have used cocaine 99 will test positive. Thus, when a randomly chosen group of people is tested for cocaine use, the vast people is tested for cocaine use, the vast majority of those who test positive will be people who have used cocaine. How to calculate？！

A reasoning error in the argument is that the argument

(A) attempts to infer a value judgment from purely factual premises

(B) attributes to every member of the population the properties of the average member of the population

(C) fails to take into account what proportion of the population have used cocaine

(D) ignores the fact that some cocaine users do not test positive

(E) advocates testing people for cocaine use when there is no reason to suspect that they have used cocaine


125.A society’s infant mortality rate is an accepted indicator of that society’s general health status. Even though in some localities in the United States the rate is higher than in many developing countries. In the United States
, overall the rate has been steadily declining. This declines does not necessarily indicate, however, that babies in the United States
are now, on the average, healthier at birth than they were in the past.
Which one of the following reasons, if true, most strongly supports the claim made above about the implications of the decline?

(A) The figure for infant mortality is compiled as an overall rate and thus masks deficiencies in particular localities.

(B) Low birth weight is a contributing factor in more than half of the infant deaths in the United States.

(C) The United States has been developing and his achieved extremely sophisticated technology for saving premature and low-birth-weight babies, most of whom require extended hospital stays.

(D) In eleven states of the United States, the infant mortality rate declined last year.

(E) Babies who do not receive adequate attention from a caregiver fail to thrive and so they gain weight slowly.





125.A society’s infant mortality rate is an accepted indicator of that society’s general health status. Even though in some localities in the United States the rate is higher than in many developing countries. In the United States
, overall the rate has been steadily declining. This declines does not necessarily indicate, however, that babies in the United States are now, on the average, healthier at birth than they were in the past.
Which one of the following reasons, if true, most strongly supports the claim made above about the implications of the decline?

(A) The figure for infant mortality is compiled as an overall rate and thus masks deficiencies in particular localities.

(B) Low birth weight is a contributing factor in more than half of the infant deaths in the United States.

(C) The United States has been developing and his achieved extremely sophisticated technology for saving premature and low-birth-weight babies, most of whom require extended hospital stays.

(D) In eleven states of the United States, the infant mortality rate declined last year.

(E) Babies who do not receive adequate attention from a caregiver fail to thrive and so they gain weight slowly.

HarrisZheng

94题说白了就是个权重问题

5%的没吸毒的人会被测出毒品，而99%的吸毒的人会测出毒品

所以结论就是被测出来毒品的人里面，多数都是吸毒的。

这个谬误很明显嘛，假定测了10000个没吸毒的，那就有500个测出毒品，然后接着又测了100个吸毒的，测出99个 500显然大于99

所以没考虑权重，也就是C说的

HarrisZheng

125就该选C啊

A是无关选项 结论本来就是说的总平均水平