3. Suppose a random variable $X$ has a CDF given by \begin{tabular}{|CC|} \hline EU & 15 \hline 19 & & \hline \end{tabular $F_{X}(x)=\left(1-e^{-x} ight) u(x) \quad (-\infty3) $ (5 points) (b) $\operatorname{Pr}(|X+1}