试题与答案

抽样调查精度的表示方法有()。 A.抽样方差的大小 B.一定置信概率下的置信区间 C

题型:多项选择题

题目:

抽样调查精度的表示方法有()。

A.抽样方差的大小

B.一定置信概率下的置信区间

C.四分位间距大小

D.标准差的大小

E.变异系数的大小

答案:

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参考答案:A, B, C

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题型:填空题

[A] A machine has been developed that pulps paper and then processes it into packaging, e.g. egg-boxes and cartons. This could be easily adapted for local authorities use. It would mean that people would have to separate their refuse into paper and non-paper, with a different dustbin for each. Paper is, in fact, probably the material that can be most easily recycled; and now, with massive increases in paper prices, the time has come at which collection by local authorities could be profitable.

[B] Recycling of this kind is already happening with milk bottles, which are returned to the dairies, washed out, and refilled. But both glass and paper are being threatened by the growing use of plastic. More and more dairies are experimenting with plastic bottles, and it has been estimated that if all the milk bottles necessary were made of plastic, then British dairies would be producing the equivalent of enough plastic tubing to encircle the earth every five or six days!

[C] The package itself is of no interest to the shopper, who usually throws it away immediately. Useless wrapping accounts for much of the refuse put out by the average London household each week. So why is it done Some of it, like the cellophane on meat, is necessary, but most of the rest is simply competitive selling. This is absurd. Packaging is using up scarce energy and resources and messing up the environment.

[D] The trouble with plastic is that it does not rot. Some environmentalists argue that the only solution to the problem of ever growing mounds of plastic containers is to do away with plastic altogether in the shops, a suggestion unacceptable to many manufacturers who say there is no alternative to their handy plastic packs.

[E] Little research, however, is being carried out on the costs of alternative types of packaging. Just how possible is it, for instance, for local authorities to salvage paper, pulp it and recycle it as egg-boxes Would it be cheaper to plant another forest Paper is the material most used for packaging--20 million paper bags are apparently used in Great Britain each day--but very little is salvaged.

[F] It is evident that more research is needed into the recovery and re use of various materials and into the cost of collecting and recycling containers as opposed to producing new ones. Unnecessary packaging, intended to be used just once, and making things look better so that more people will buy them, is clearly becoming increasingly absurd. But it is not so much a question of doing away with packaging as using it sensibly. What is needed now is a more sophisticated approach to using scarce resources for what is, after all, a relatively unimportant function.

[G] To get a chocolate out of a box requires a considerable amount of unpacking: the box has to be taken out of the paper bag in which it arrived; the cellophane wrapper has to be torn off, the lid opened and the paper removed; the chocolate itself then has to be unwrapped from its own piece of paper. But this insane amount of wrapping is not confined to luxuries. It is now becoming increasingly difficult to buy anything that is not done up in cellophane, polythene or paper.

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题型:多项选择题 案例分析题

某城市用地面积600平方公里,全市有公共交通线路通过的街道长度为2100公里,拥有公交营运车辆800辆,公交线路长度为3000公里。统计调查资料显示,该城市公交车的平均营运速度为30公里/小时,居民步行速度为4公里/小时。市政府最近提出:要在公共交通车辆既定的情况下,通过优化线网密度不断提高城市居民的出行方便程度,使城市95%的居民的单程出行时间缩短到40分钟以内。

该城市较高的公交线网密度将会导致乘客()。

A.步行时间缩短

B.候车时间缩短

C.步行时间延长

D.候车时间延长

E.乘车时间延长

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