Question

Estimate the minimum sample size needed to achieve the margin of error E equals = 0.293

Answer 1

Solution :

Given that,

= 0.5

1 - = 1 - 0.5 = 0.5

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z_/2 = Z_0.025 = 1.96

sample size = n = (Z _{/ 2} / E )² * * (1 - )

= (1.96 / 0.293)² * 0.5 * 0.5

= 11.18 = 12

Minimum sample size = 12