Math

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Let X and Y be normal random variables with means 0 and 2, respectively, and variances 1 and 9, respectively. Find the following, using the standard normal table. Express your answers to an accuracy of 4 decimal places.

P(X>0.75)=
P(X≤−1.25)=
Let Z=(Y−3)/4. Find the mean and the variance of Z.

E[Z]=
var(Z)=
P(−1≤Y≤2)=

  • Math (Partial) -

    First two questions and last.

    Z = (score-mean)/SD

    SD^2 = variance

    Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability of the Z score.

  • Math -

    P(X>0.75)= 0.2266
    P(X≤−1.25)= 0.1056


    Can't figure out these:
    E[Z]=
    var(Z)=
    P(−1≤Y≤2)=

    anyone?

  • Math -

    P(X>0.75)= 0.2266
    P(X≤−1.25)= 0.1056
    E[Z]= -1/4
    var(Z)= 9/16
    P(−1≤Y≤2)= ?

  • Math -

    P(−1≤Y≤2)= 0.3413

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