Exercise: Sections of a class A class consists of three sections of 10 students each. The average quiz scores in each section were 40, 50, 60, respectively. We choose a student, uniformly at random. Let X be the score of the selected student, and let Y be his section number. The quantity var(X|Y=y) was found to be equal to 5y for each section (y=1,2,3).
(a) The random variable E[X|Y] has:
average :
50
a difference of:
66.66667
(be[var(X|Y)]=
ten
(c) var(X)=
76.66667
(no need to answer) I also banned you from posting here. I am deleting your many probability messages. Obviously you post them so that other students can cheat.
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