Answer:
324
Step-by-step explanation:
given that in a poll, 74% of the people polled answered yes to the question "Are you in favor of the death penalty for a person convicted of murder?"
i.e. Sample proportion [tex]p=0.74\\q =1-p =0.26\\[/tex]
Margin of error = 4% = 0.04
Confidence level =90%
Z critical value for 90% = 1.645
Margin of error = 1.645 * std error
Hence std error = [tex]\frac{0.04}{1.645} \\=0.0243[/tex]
Std error is also equal to
[tex]\sqrt{\frac{pq}{n} } =\sqrt{\frac{0.74(0.26)}{n} } =0.0243\\\sqrt{n} =18..05\\n = 325.83~324[/tex]
Sample size should be 324.
The formula is sample size = (Z critical value)^2 (pq)/(Margin of error )^2
