NO.PZ2015120604000060
问题如下:
According to the above table, what is the expected return of X?
选项:
A.1.
B.1.6.
C.-3.2.
解释:
A is correct
Expected return of X= (0.2)(-2) + (0.6)(1) + (0.2)(4) = 1
老师,以第一格数据为例,0.2是joint probability,那就应该是P(XY)的概率,但为什么在计算的时候就直接把它当作P(X)的概率了呢?