Answer: [tex]5\pm2[/tex]
Explanation:
Given : The probability of developing breast cancer among smokers : [tex]p=0.05[/tex]
Sample size = 100
The mean for binomial distribution is given by :-
[tex]\mu=np=0.05\times100=5[/tex]
The standard deviation for binomial distribution is given by :-
[tex]\sigma=\sqrt{np(1-p)}[/tex]
[tex]\Rightarrow\sigma=\sqrt{100(0.05)(1-0.05)}\\\\\Rightarrow\sigma=2.1794494717\approx2[/tex]
The expected number of people will develop the disease is given by :-
[tex]\mu\pm\sigma=5\pm2[/tex]