狒狒逻辑题目求解~~~

紫落 · 发表于 2010-7-13 21:26:20

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.
A reasoning error in the argument is that the arguement...
A.attempts to infer a value judgement 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
讲解上面说的比例算法没怎么看懂X:non-usersY:users.5%X<99%Y→X<99/5Y,希望能有NN给解释下~知道reasoning里面的错误是对随机选择的group people中cocaine users和non-users的比例的错误推断，不过对各个他选项的解释不是很明白~希望能更明白点的解释~~先谢谢啦~~

狒狒逻辑题目求解~~~

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