4 A random variable \(X\) has probability density function given by
$$f ( x ) = \begin{cases} \frac { 1 } { 18 } \left( 9 - x ^ { 2 } \right) & 0 \leqslant x \leqslant 3
0 & \text { otherwise } \end{cases}$$
- Find \(\mathrm { P } ( X < 1.2 )\).
- Find \(\mathrm { E } ( X )\).
The median of \(X\) is \(m\). - Show that \(m ^ { 3 } - 27 m + 27 = 0\).