假设你是一家负债率很高的公司的惟一股东。该公司的所有债务在1年后到期。如果到时公司的价值高于

某公司股票收益率和股票市场收益率的有关数据如下表所示：

求：(1)股市及A公司股票的期望收益率与标准离差；

(2)A公司股票与市场的相关系数；

(3)A公司股票的β系数。

若此时无风险报酬率为6%，股票市场的平均收益率为10%，A公司股票的贝塔系数为2，公司目前的股价为18元，求：

(1)股票的价值；

(2)股票预期的投资收益率。

y a society is grossly inaccurate, its education system will betray its youth.

Imagine an Indian tribe which for centuries has sailed its dugouts on the river at its doorstep. During all this time the economy and culture of the tribe have depended upon fishing, preparing and cooking the products of the river, growing food in soil fertilized by the river, building boats and appropriate tools. (2) So long as the rate of technological change in such a community stays slow, so long as no wars, invasions, epidemics or other natural disasters upset the even rhythm of life, it is simple for the tribe to formulate a workable image of its own future, since tomorrow merely repeats yesterday.

It is from this image that education flows. Schools may not even exist in the tribe; yet there is a curriculum—a cluster of skills, values and rituals to be learned. Boys are taught to scrape bark and hollow out trees just as their ancestors did before them. The teacher in such a system knows what he is doing, secure in the knowledge that tradition—the past—will work in the future.

(3) What happens to such a tribe, however, when it pursues its traditional methods unaware that five hundred miles upstream men are constructing a gigantic dam that will dry up their branch of the river? Suddenly the tribe's image of the future, the set of assumptions on which its members base their present behavior, becomes dangerously misleading. Tomorrow will not replicate today. The tribal investment in preparing its children to live in a river culture becomes a pointless and potentially tragic waste. A false image of the future destroys the relevance of the education effort.

This is our situation today—only it is we, ironically, not some distant strangers—who are building the dam that will annihilate the culture of the present. (4) Never before has any culture subjected itself to so intense and prolonged a bombardment of technological, social, and info-psychological change. (5) This change is accelerating and we witness everywhere in the high-technology societies evidence that the old industrial-era structures can no longer carry out their functions.

两所学校计算机算法语言学习小组参加一项同意测验，结果如下：

甲校：16，12，20，15，23，8，16，19；

乙校；22，17，．16，24，8，7，25，28；

请选择一种参数检验方法和中位数检验方法，分析甲乙两校计算机算法测验成绩是否有显著性差异。