Question

Question 17 (1 point) The Reform party of BC is considering forming as a party again. They would like to gauge public support. They asked the question "would you consider voting for the Reform party?" 6/30 people said the would. They would like to reduce the margin of error to 5% or less at the 95% confidence level. How large a sample should they select? Your Answer:

Answer 1

Given : MArgin oe error=E=5%=0.05

The estimate of the proportion is ,

P= * = 0.20

Significance level=

= 0,05

Now , $Z_{\alpha/2}=Z_{0.05/2}=1.96$ ; From standard normal distribution table

Therefore , the required sample size is ,

$n=\frac{Z_{\alpha/2}^2*\hat{p}(1-\hat{p})}{E^2}=\frac{1.96^2*0.20(1-0.20)}{0.05^2}=245.8624\approx 246$