NO.PZ2015120604000086
问题如下:
Which of the following statements is the most correct?
选项:
A.The expected value of X is 2.87.
B.The expected value of X is 3.74.
C.The expected value of X is 8.23.
解释:
A is correct.
E(X)=0(0.14)+1(0.09)+2(0.19)+3(0.25)+4(0.17)+5(0.06)+6(0.03)+7(0.07)=2.87
在expected value 方差的公式中括号里(Xi-EX)的EX就是expected value的值吗?EX代表的是什么