Earthquakes in another country Assume that in an other country the probability that during a year at least one earthquake happens is 0,3 . What is the probability that during 5 years the number of earthquakes is at least 3? Note: We need to apply "Poisson Distribution" for solving this problem.
Hi guys. I solved this problem with help of simple proportion. I said that if during 1 year probability is 0.3 , then during 5 is X and found X which is 1,5 . Thus probability is 1,5 . I just want to make sure that the result is right. Thanks in advance!
If you want to use a Poisson distribution, the expected number in five years is $1.5$. That is the $\lambda$ parameter in the distribution, so the probability of $n$ earthquakes in $5$ years is $$P(n)=\frac {1.5^ne^{-1.5}}{n!}$$Now compute the probability of $0$ to $2$ earthquakes and subtract from $1$ to get the chance of at least $3$ earthquakes.