A.高水位地区深基坑内必须设置有效的降水措施
B.基坑施工必须设置有效的排水措施
C.深基坑边界周围地面必须设置排水沟
D.深基坑降水施工必须有防止临近建筑及管线危险的防止沉降措施
假设一位投资者关心的某项商业项目可能有三个前景——其概率与回报如下表所示。
这项不确定性投资的期望收益、方差各是多少?
Suppose an investor is concerned about a business choice in which there are three prospects -the probability and returns are given below:
What is the expected value of the uncertain investment? What is the variance?