Let ZN01 Create an rv YN14 as a simple looking function of Z
Let Z~N(0,1). Create an r.v. Y~N(1,4), as a simple looking function of Z. Make sure to check that your Y has the correct mean and variance.
Solution
We will have to use basic properties of mean and variances .
Properties.
E(aX) = aE(X)
E(X+b) = E(X) +b
Var(aX) = a2Var(X)
Var(X+b) = Var(X)
Using these properties if ,
Y = 2Z +1
The
E(Y) = E(2Z+1) = E(2Z) +1 = 2E(Z) +1 = 0
Var(Y) = Var(2Z+1) = Var(2Z) = 22Var(Z) = 4*1 = 4.
This our random variable Y must be such that,
Y = 2Z +1
