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Normal Random Variables Question 
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#1
May2910, 10:58 PM

P: 2

1. The problem statement, all variables and given/known data
Problem 1 – Normal Random Variables B) Y ~ N(300, 100). Pr (300 < Y < 320) = 0.4772 D) H ~ N(4000, 25). R = f(H) = 0.5H – 60. E(R) = 1940; Var(R) = 156.25 I have a problem solving these problems above...I missed the class when we covered this subject and now I am lost upon solving them.. I hope somebody can help, thanks a lot 


#2
May3010, 09:12 AM

HW Helper
P: 1,371

For a normally distributed random variable,
[tex] P(a < X < b) = P(X < b)  P(X < a) [/tex] For any random variable [itex] W [/itex], if [itex] a, b [/itex] are real numbers, and [tex] Z = aW + b [/tex] then [tex] E(Z) = aE(W) + b, \quad Var(Z) = a^2 Var(W) [/tex] (as long as the mean and variance of [itex] W [/itex] exist) 


#3
May3110, 11:34 AM

P: 2

Thanks for the reply!!
However, when I plug it in I dnt get the right answer.... did u check if the given answer is right? 


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