3 The discrete random variable \(A\) has the following probability distribution function
$$\mathrm { P } ( A = a ) = \begin{cases} 0.45 & a = 0 0.25 & a = 1 0.3 & a = 2 0 & \text { otherwise } \end{cases}$$
3
Find the median of \(A\)
3
Find the standard deviation of \(A\), giving your answer to three significant figures.
3
\(\quad\) Find \(\operatorname { Var } ( 9 A - 2 )\)