問題詳情

257. Let X be the percentage score on a college-entrance exam for students who did not participate in an exam-preparation seminar. X is modeled by a uniform distribution on [a, 100]. Let Y be the percentage score on a college-entrance exam for students who did participate in an exam-preparation seminar. Y is modeled by a uniform distribution on [1.25a, 100]. It is given that

.
 Calculate the

 percentile of Y.
(A) 80
(B) 85
(C) 90
(D) 92
(E) 95

參考答案

答案：E

統計：A:1,B:0,C:0,D:0,E:0

難度：計算中