4:06 9 webwork.smith.edu ooO AT&T; LTE PreviouS Problem List Next (1 point) Four

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4:06 9 webwork.smith.edu ooO AT&T; LTE PreviouS Problem List Next (1 point) Four buses carrying 160 high school students arrive to Montreal. The buses carry, respectively, 33, 46, 34, and 47 students. One of the studetns is randomly selected. Let Xl denote the number of students that were on the bus carrying this randomly selected student. One of the 4 bus drivers is also randomly selected. Let Yldenote the number of students on his bus. Compute the expectations and variances of Xland Y: E(X) =1 41.06 Var(X) =| 41.57? E(Y 40 Var(Y) 42.5 Note: You can earn partial credit on this problem. Preview My Answers Submit Answers

Explanation / Answer

E(X)=33*33/160+34*34/160+46*46/160+47*47/160=41.0625

E(Y)=33*1/4+34*1/4+46*1/4+47*1/4=40

Var(X)=33^2*33/160+34^2*34/160+46^2*46/160+47^2*47/160=1727.5

Var(Y)=33^2*1/4+34^2*1/4+46^2*1/4+47^2*1/4=1642.5

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