6 The discrete random variable \(X\) has probability distribution function
$$\mathrm { P } ( X = x ) = \begin{cases} a & x = 0
b & x = 1
c & x = 2
0 & \text { otherwise } \end{cases}$$
where \(a , b\) and \(c\) are constants.
The mean of \(X\) is 1.2 and the variance of \(X\) is 0.56
6
- Deduce the values of \(a , b\) and \(c\)
6 - The continuous random variable \(Y\) is independent of \(X\) and has variance 15
Find \(\operatorname { Var } ( X - 2 Y - 11 )\)
[0pt]
[2 marks]