Answer: 2017
Step-by-step explanation:
Given : The proportion of people that smoke : p=0.3
Margin of error : E= 0.02
Significance level :[tex]\alpha=1-0.95=0.05[/tex]
Critical value : [tex]z_{\alpha/2}=1.96[/tex]
The formula to calculate sample size ( if proportion is known) :-
[tex]n=p(1-p)(\dfrac{z_{\alpha/2}}{E})^2\\\\\Rightarrow\ n=(0.3)(0.7)(\dfrac{(1.96)}{0.02})\\\\\Rightarrow\ n=2016.84approx2017[/tex]
Hence, the required minimum sample would be 2017.