YAMT: Expected values and Variances ??

[Syringer]

This is the problem..

E[x]=1, Var(x)=5

I have to find..a) E((2+x)^2)

and b) Var(4+3x)

The book is pretty worthless and I have no idea how to go through this. Help?

 

[dighn]

welll from my last year's ststa lecture notes

if Y = aX + b

then Var(Y) = a^2Var(X)

dunno about E though

 

[Syringer]

Ah, that works for the second part..still not sure about the first part though..

 

[Syringer]

N/m, I got it!