In: Statistics and Probability
QUESTION 1. On average, one in every 1000 people living in a
city is known to have cancer. In a study carried out in this
province, 5000 people were checked for health. According to
this;
a) Calculate the probability that 7 out of 5000 people will get
cancer.
b) Calculate the probability that no more than 1 person out of 5000
can get cancer.
Given,
Average number of people having cancer in every 1000 people = 1
Average number of people having cancer in every 5000 people = 5
X : Number of people out of 5000 people will get cancer
X follows Poisson distribution with 
 = 5
Probability mass function of X is given by
Probability that 'x' number of people out of 5000 people will
have cancer = P(X=x)
a) Probability that 7 out of 5000 people will get cancer = P(X=7)

Probability that 7 out of 5000 people will get cancer = 0.1044
b)  probability that no more than 1 person out of 5000
can get cancer = P(X
1)
= P(X=0)+P(X=1)


P(X=0)+P(X=1) = 0.006737947+0.033689735 = 0.040427682
0.0404
probability that no more than 1 person out of 5000 can get cancer =0.0404