Normal Random Variables Question

  1. 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. jcsd
  3. statdad

    statdad 1,478
    Homework Helper

    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)
     
  4. 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?
     
Know someone interested in this topic? Share a link to this question via email, Google+, Twitter, or Facebook

Have something to add?