| Exam Board | CAIE |
|---|---|
| Module | S2 (Statistics 2) |
| Year | 2020 |
| Session | June |
| Paper | Download PDF ↗ |
| Topic | Poisson Distribution |
4 The random variable $A$ has the distribution $\operatorname { Po } ( 1.5 ) . A _ { 1 }$ and $A _ { 2 }$ are independent values of $A$.\\
(a) Find $\mathrm { P } \left( A _ { 1 } + A _ { 2 } < 2 \right)$.\\
(b) Given that $A _ { 1 } + A _ { 2 } < 2$, find $\mathrm { P } \left( A _ { 1 } = 1 \right)$.\\
(c) Give a reason why $A _ { 1 } - A _ { 2 }$ cannot have a Poisson distribution.\\
\hfill \mbox{\textit{CAIE S2 2020 Q4}}