Mathematics 9709 · AS & A Level · The Poisson distribution

The Poisson distribution — practice question

$X$ is a random variable with distribution $\text{Po}(1.5)$. Let $S$ denote the total of three independent values of $X$.

(a)[3]

Find the value of $P(S \leq 3)$.

(b)[3]

Show that $\frac{P(S \leq 2)}{P(S \leq 1)}$ equals $\frac{125}{44}$ exactly.

Worked solution & mark scheme

This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Correctly identifies $\lambda = 4.5$” …