分层抽样与整群抽样有何异同？它们分别适合于什么场合？
参考答案：
相同点：分层抽样和整群抽样都需要事先按某一标志对总体进行划分的随机抽样。（2分）
不同点：
（1）分层抽样的划分标志与调查标志有密切关系，而整群抽样的划分标志不一定与调查标志有关。（1分）
（2）分层抽样是在各层中随机抽样，而整群抽样在全部群中随机抽取一部分群体。（1分）
（3）分层抽样的抽样误差取决于各层总体方差的平均数，整群抽样的抽样误差取决于总体的群间方差。（1分）
（4）分层抽样的目的主要是缩小抽样误差，满足推断子总体数量特征的需要，而整群抽样的目的主要是扩大抽样单位，简化组织工作。（1分）适用场合：分层抽样用于层间差异大而层内差异小时，以及为了满足分层次管理决策的需要。（2分）整群抽样用于群间差异小而群内差异大时，或只有经群体为抽样单位的抽样框等。（2分）
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| Ain’t What I Used to Be It has been said, "Be contented with what you have, but never too__1__with what you are." There is a story about a farmer who saw a tiger’s tail__2__between two large rocks.In a hurry, he seized the tail and__3__. All of a sudden he realized he had an angry tiger by the__4__and only two__5__stood between him and the tiger's teeth and claws! So there he remained, __6__to loosen his hold on the__7__ animal's tail in case he will surely be killed. A monk happened to go by and the farmer called out in__8__, "Come over here and help me.__9__ this tiger!" The monk said, "Oh, no. I cannot do that. I cannot take the__10__of another." Then he went on to deliver a long__11__against killing. All the while, the farmer was holding__12__to the tail of the angry tiger. When the monk finally finished his__13__, the farmer asked, "If you won't kill the tiger, then__14__ come and hold its tail while I kill it." The monk thought that perhaps, it would be all right to__15__hold the tiger's tail, so he__16__and pulled.The farmer, however, turned and walked away down the road. The monk__17__after him, "Come back here and kill the tiger!" "Oh, no," the farmer replied. "You have__18__me!" If the largest room in the world is "room for improvement", then it is good to leave__19__of room for change. A life of change! A life of growth! And always leaving room for__20__. It's the only way to live. | ||||
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