Answer to Question #169312 in Statistics and Probability for j

Question

What sample size should be obtained to determine a 94% confidence within 4%?

Answer 1

Sample size formula:

$n = \frac{Z_{α/2}^2 pq}{E^2}$

P unknown:

$n = \frac{Z_{α/2}^2 0.25}{E^2}$

Determine $Z_{α/2}$ for confidence level of 94% using table:

$Z_{0.03} = 1.89$

$n = \frac{1.89^2 \times 0.25}{0.04^2} = \frac{0.893}{0.0016} = 558$

Answer: 558