2. The discrete random variable \(X\) has the probability function shown below.
$$P ( X = x ) = \left\{ \begin{array} { l c }
\frac { k } { x } , & x = 1,2,3,4
0 , & \text { otherwise } .
\end{array} \right.$$
- Show that \(k = \frac { 12 } { 25 }\)
Find
- \(\mathrm { F } ( 2 )\),
- \(\mathrm { E } ( X )\),
- \(\mathrm { E } \left( X ^ { 2 } + 2 \right)\).