4 The random variable \(A\) has the distribution \(\operatorname { Po } ( 1.5 ) . A _ { 1 }\) and \(A _ { 2 }\) are independent values of \(A\).
- Find \(\mathrm { P } \left( A _ { 1 } + A _ { 2 } < 2 \right)\).
- Given that \(A _ { 1 } + A _ { 2 } < 2\), find \(\mathrm { P } \left( A _ { 1 } = 1 \right)\).
- Give a reason why \(A _ { 1 } - A _ { 2 }\) cannot have a Poisson distribution.