問題詳情

57. The warranty on a machine specifies that it will be replaced at failure or age 4, whichever occurs first. The machine’s age at failure, X, has density function


 Let Y be the age of the machine at the time of replacement.
Calculate the variance of Y.
(A) 1.3
(B) 1.4
(C) 1.7
(D) 2.1
(E) 7.5

參考答案

答案：C

統計：A:0,B:0,C:0,D:0,E:0

難度：計算中