作者Vanisha (no)
看板Math
标题[机统] 掷骰问题
时间Sun Aug 14 17:49:00 2011
The random variable X is defined by taking the square of the score obtained
by rolling an unbiased dice once.
计算出
x= 1 4 9 16 25 36
p(X=x) 1/6 1/6 1/6 1/6 1/6 1/6
F(x) 1/6 2/6 3/6 4/6 5/6 6/6
E(X)= 15.17
Var(X)用 1x(1-15.17)^2 +.....+ 1x(36-15.17)^2 /6 =149.13
答案跟解答379.14不符合
请问是哪边出错了呢? 谢谢~
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