Mathematics 9709 · AS & A Level · The Poisson distribution

The Poisson distribution — practice question

Answer the following using suitable approximating distributions.
(a(i))[3]

The random variable $W$ follows the distribution $B(700, 0.005)$. Calculate $P(W \geq 4)$.

(a(ii))[3]

Two values of $W$ are selected at random. Find the probability that their sum is less than $3$.

(b)[4]

The random variable $X$ has distribution $\operatorname{Po}(200)$. Use a suitable approximating distribution to find $P(X > 205)$.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Recognising the mean $\lambda=3.5$

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI