点估计是用样本的统计量直接估计和代表总体参数。()

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问题:

点估计是用样本的统计量直接估计和代表总体参数。()

考点:统计师考试统计基础理论及相关知识参数估计
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机动车在消防栓或者消防队(站)门前()米以内的路段,不得停车。

A.30

B.20

C.10

D.5

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Bernard Jackson is a free man today, but he has many bitter memories. Jackson spent five, years in prison after a jury wrongly convicted him of raping two women. At Jackson’s trial, although two witnesses testified that Jackson was with them in another location at the times of the crimes, he was convicted anyway. Why The jury believed the testimony of the two victims, who positively identified Jackson as the man who had attacked them. The court eventually freed Jackson after the police found the man who had really committed the crimes. Jackson was similar in appearance to the guilty man. The two women had made a mistake in identity. As a result, Jackson has lost five years of his life.

The two women in this case were eyewitnesses. They clearly saw the man who attacked them, yet they mistakenly identified an innocent person. Similar incidents have occurred before. Eyewitnesses to other crimes have identified the wrong person in a police lineup or in photographs.

Many factors influence the accuracy of eyewitness testimony. For instance, witnesses sometimes see photographs of several suspects before they try to identify the person they saw in a line-up of people. They can become confused by seeing many photographs or similar faces. The number of people in the line-up, and whether it is a live line-up or a photograph, may also affect a witness’s decision. People sometimes have difficulty identifying people of other races. The questions the police ask witnesses also have an effect on them.

Are some witnesses more reliable than others Many people believe that police officers are more reliable than ordinary people. Psychologists decided to test this idea, and they discovered that it is not true. Two psychologists showed a film of crimes to both police officers and civilians. The psychologists found no difference between the police and the civilians in correctly remembering the details of the crimes.

Despite all the possibilities for inaccuracy, courts cannot exclude eyewitness testimony from a trial. American courts depend almost completely on eyewitness testimony to resolve court cases. Sometimes it is the only evidence to a crime, such as rape. Furthermore, eyewitness testimony is often correct. Although people do sometimes make mistakes, many times they really do identify individuals correctly.

American courts depend on the ability of the 12 jurors, and not the judges, to determine the accuracy of the witness’s testimony. It is their responsibility to decide if a certain witness could actually see, hear, and remember what occurred.

In a few cases, the testimony of eyewitnesses has convicted innocent people. More importantly, it has rightly convicted a larger number of guilty people; consequently, it continues to be of great value in the American judicial system.

According to the passage, who are in a position to decide whether a witness testimony is reliable?()

A.The police.

B.The prosecutors.

C.The judges.

D.The jurors.

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园艺植物茎的分枝方式分为()、()、()、().

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请问拜论是哪个国家的伟大的浪漫主义诗人?()

A.法国

B.瑞士

C.英国

D.意大利

题型:判断题

下列关于细胞结构的叙述,正确的是()

A.有线粒体的细胞一定是真核细胞

B.高尔基体能合成和分泌多种消化酶

C.细胞内的酶都分布在生物膜上

D.细胞膜上的蛋白质都与物质运输有关

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