Answer: Required minimum sample size = 2017
Step-by-step explanation:
Formula : Sample size(n) for population proportion(p):
[tex]n= p(1-p)(\frac{Z^c}{E})^2[/tex] , where E = Margin of error
If p = proportion of smokers
Given: p =0.30 and E=0.02
[tex]z^c[/tex] for 95% confidence level = 1.96
So,
[tex]n=0.30(1-0.30)(\dfrac{1.96}{0.02})^2\\\=0.30(0.70)(98)^2\\\\=2016.84\approx2017[/tex]
Hence, required minimum sample size = 2017