Answer: 1692
Step-by-step explanation:
if prior estimate of proportion is not known , then the formula to find the sample size is given by:-
[tex]n=0.25(\dfrac{z_{\alpha/2}}{E})^2[/tex] (1)
For 90% confidence interval , significance level =[tex]\alpha=1-0.90=0.10[/tex]
Critical value =[tex]z_{\alpha/2}=1.645[/tex]
Margin error = 0.02
Now, substitute all the above values in (1), we get
[tex]n=0.25(\dfrac{1.645}{0.02})^2=1691.265625\approx1692[/tex]
Hence, the required minimum sample size should be 1692.
