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问题 单项选择题 A1/A2型题

在正态分布的情况下，横轴上，从均值μ到μ+1.96倍的标准差的面积为（）.

A.45%

B.47.5%

C.50%

D.95%

E.97.5%

答案

参考答案：B

解析：在正态分布的情况下，横轴上，从均值μ到μ+1.96倍的标准差的面积为47.5%。

单项选择题 B1型题

对于一个分布不明的资料，或是分布一端或两端出现不确定值，用于描述其集中趋势是（）

A.均数

B.几何均数

C.中位数

D.标准差

E.四分位数间距
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单项选择题

In looking at the class structure of an entire system, we may find that its inheritance (1) is either wide and shallow, narrow and deep, or balanced. Class structures that are wide and shallow usually represent forests of (2) classes that can be mixed and matched. Class structures that are narrow and deep represent trees of classes that are related by a common ancestor. There are advantages and disadvantages to each approach. Forests of classes are more loosely (3) , but they may not exploit all the commonality that exists. Trees of classes exploit this commonality, so that individual classes are smaller than in forests. However, to understand a particular class, it is usually necessary to understand the meaning of all the classes it inherits from or uses. The proper shape of a class structure is highly problem-dependent.
We must make similar trade-offs among inheritance, aggregation, and using relation- ships. For example, should the class Car inherit, contain, or use the classes named Engine and Wheel In this case, we suggest that an (4) relationship is more appropriate than inheritance relationship. Meyer states that between the class A and B," (5) is appropriate if every instance of B may also be viewed as an instance of A. The client relationship is appropriate when every instance of B simply possesses one or more attributes of A". From another perspective, if the behavior of an object is more than the sum of its individual parts, then creating an aggregation relationship rather than an inheritance relationship between the appropriate classes is probably superior.

(3)

A．dispersive

B．cohesion

C．coupled

D．close-knit
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