Question
The moment generating function of $X$ is given by $M_{X}(t)=\exp \left\{2 e^{t}-2\right\}$ and that of $Y$ by $M_{Y}(t)=\left(\frac{1}{4}\right)^{10}$. If $X$ and $Y$ are independent, what are(a) $P\{X+Y=2\}$;(b) $P\{X Y=0\}$;(c) $E[X Y]$ ?
Step 1
Since $X$ and $Y$ are independent, the moment generating function of $X+Y$ is the product of the moment generating functions of $X$ and $Y$. Therefore, we have \[M_{X+Y}(t) = M_X(t)M_Y(t) = \exp\{2e^t - 2\}\left(\frac{1}{4}\right)^{10}.\] Show more…
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