SOLUTION: please help me in this let x have the p.d.f f(x)= (x+2)/18 , -2<x<4 , zero elsewhere find E[(x+2)^3], and E[6x-2(x+2)^3]

Algebra ->  Probability-and-statistics -> SOLUTION: please help me in this let x have the p.d.f f(x)= (x+2)/18 , -2<x<4 , zero elsewhere find E[(x+2)^3], and E[6x-2(x+2)^3]      Log On


   

Question 60607This question is from textbook introduction to mathmatical statistics
: please help me in this
let x have the p.d.f f(x)= (x+2)/18 , -2 find E[(x+2)^3], and E[6x-2(x+2)^3] This question is from textbook introduction to mathmatical statistics

Found 2 solutions by stanbon, NM653264:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
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Answer by NM653264(1) About Me  (Show Source):
You can put this solution on YOUR website!
E(X) = the integral from 4 to -2 of xf(x)dx
=Integral of x(x+2/18) = (x^2+2x)/18
now integrate from -2 to 4 so you get E(X)=2
E((x+2)^3) = E(2+2)^3 =64
E[6x-2(x+2)^3]=6(2)-2(64) = -116