Which of the following most logically completes the argument?
Researchers recently asked dozens of shoppers, chosen at random coming out of a FoodBasket supermarket, what they had purchased. The prices of the very same items at the nearest ShopperKing supermarket were totaled and compared with the FoodBasket total. The ShopperKing totals averaged five percent higher than the FoodBasket totals. Nevertheless, this result does not necessarily show that shoppers at ShopperKing would save money overall by shopping at FoodBasket instead, since ______.
Q40: Which of the following most logically completes the argument?
Researchers recently asked dozens of shoppers, chosen at random coming out of a FoodBasket supermarket, what they had purchased.The prices of the very same items at the nearest ShopperKing supermarket were totaled and compared with the FoodBasket total.The ShopperKing totals averaged five percent higher than the FoodBasket totals.Nevertheless, this result does not necessarily show that shoppers at ShopperKing would save money overall by shopping at FoodBasket instead, since ______.
shoppers who shop regularly at a given supermarket generally choose that store for the low prices offered on the items that they purchase most often
for shoppers with more than 20 items, the ShopperKing totals averaged more than five percent higher than the FoodBasket totals
many shoppers consider factors other than price in choosing the supermarket at which they shop most regularly
there is little variation from month to month in the overall quantity of purchases made at supermarkets by a given shopper
none of the people who conducted the research were employees of the FoodBasket supermarket
这题好像不是这个意思。它的论证过程属于归纳推理,尤其是归纳推理早期的那种枚举推理。Research调查的是从FB出来的客户,把他们买的几样东西和SK的产品进行价格比较,然后得出:仅针对比较的产品,SK计算出的平均价格比FB的平均价格高。Main conclusion说这不对,因为......, SK的overall产品不一定比FB贵。
我第一次也错选成B。后来想想,如果选不对,可能是不太理解答案A的意思。答案A说shoppers在FB买东西,当然选FB便宜的东西买。这充分说明research选取样本有问题,因为SK可能这几样东西价格贵,不代表其他东西都贵,sample bias。虽然GMAC用chosen at random coming out of ...这样的字眼迷惑我们,但同时给我们信息,所谓的random不是真正的random。
归纳推理是不严谨的推理,有两类缺陷(也是assumptions):
1. some number of observations of particular instances --> generalizing about the properties of a class of objects; 容易以偏概全
2. Presupposing that a sequence of events in the future will occur as it always has in the past; 过去和未来不一定一样
我用考试时候时“晕菜”的方法解这个题:
Nevertheless, this result does not necessarily show that shoppers at ShopperKing would save money overall by shopping at FoodBasket instead 说的是在哪个超市买东西省不省钱的问题。
A. 相关。讨论的“省钱”的问题
B. 相关。讨论“省钱”的问题。
C. 不相关:讨论“除了价格以外的因素”
D. 不相关:讨论质量问题
E. 不相关:讨论什么人做调查
A与B比看范围:
A: shoppers who shop regularly at a given supermarket
B: for shoppers with more than 20 items
A的范围大,范围越大支持力度越强。B只说了for shoppers with more than 20 items,那买少于20个东西的呢?没说。
选A。