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Find E(Y^2) and Var(100Y-35)

I don't really know where to start.. any suggestions? I know that variance = Var(Y) = E[Y - mean]^2

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Use the following properties :

$$ E(aY+b)=aE(Y)+b$$

$$V(aY+b)=a^2V(Y)$$

$$ V(Y)=E(Y^2)-E(Y)^2$$

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    so using the first property I found that 3E(Y) + 7 = 19 so E(Y) = 4. Does this imply that E(Y^2) = 16? How can i use the other properties to solve for Var(100Y-35) – 2017-02-22
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    No no no!!!!!!! – 2017-02-22
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    It emphatically does **not** mean that $E(Y^2)=16$. If you can also determine $V(Y)$ then you can use the third property to help you determine $E(Y^2)$. – 2017-02-22
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    okay so V(Y) = 25 by property 2 and then 25 = E(Y^2) -4^2 so E(Y^2) = 41... is this right? – 2017-02-22
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    Yup thats right – 2017-02-22