In: Statistics and Probability
An insurance company insures 2,000 people each year, each of whom has a 1/1000 chance of an accident in 1 year. Use the Poisson approximation to compute the probability that there will be at most 2 accidents. Also, calculate the exact binomial-(n,p) probability
Ans:
Given that
n=2000
p=1/000
Poisson approximation:
mean=np=2000*(1/000)=2
P(x=k)=exp(-2)*(2^k/k!)
P(at most 2)=P(x<=2)
=P(x=0)+P(x=1)+P(x=2)
=exp(-2)*(2^0/0!+2^1/1!+2^2/2!)=0.6767