問題詳情

232. The number of claims X on a health insurance policy is a random variable with

 E[X2]=61 and E[X-1]2=47.

Calculate the standard deviation of the number of claims.
(A) 2.18
(B) 2.40
(C) 7.31
(D) 7.50
(E) 7.81

參考答案

答案:A

統計:A:0,B:0,C:0,D:0,E:0

難度:計算中