# Poisson Q help plz

• May 4th 2009, 04:42 PM
JJC85
Poisson Q help plz
Hey ppl,

can u help me on this question plz.

An insurance company is reassessing the risk of flooding. From past records it
has calculated that on average the low lying village of Hogwash gets flooded
once every 100 years.

(a) Using the Poisson distribution with mean 1 find the probability that in
the next hundred years it is flooded

(i) at least once,

(ii) exactly twice.

(b) On average how many times will it be flooded in the next 500 years?
Using your answer find the probability that it is flooded at most 4 times
in the next 500 years.
• May 4th 2009, 07:58 PM
mr fantastic
Quote:

Originally Posted by JJC85
Hey ppl,

can u help me on this question plz.

An insurance company is reassessing the risk of flooding. From past records it
has calculated that on average the low lying village of Hogwash gets flooded
once every 100 years.

(a) Using the Poisson distribution with mean 1 find the probability that in
the next hundred years it is flooded

(i) at least once,

(ii) exactly twice.

(b) On average how many times will it be flooded in the next 500 years?
Using your answer find the probability that it is flooded at most 4 times
in the next 500 years.

(a) Calculate $\displaystyle \Pr(X \geq 1) = 1 - \Pr(X = 0)$ and $\displaystyle \Pr(X = 2)$.

(b) $\displaystyle \lambda = 5$. Calculate $\displaystyle \Pr(X \leq 4)$.

Where are you stuck?