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 E[X2]=19,6003. Calculate the 80th percentile of Y.
a. 80.
b. 85.
c. 90.
d. 92.
e. 95.