Question

The Airport Transit Authority wants to estimate, with 95% confidence, the proportion of adults that they have never flown in an airplane. It is desired the estimate be accurate to within 3% of the population proportion. The minimum sample size needed is closest to a) 1225 b) 1692 c) 2401 d) 49 e) 1068

Answer 1

Solution :

Given that,

= 0.5

1 - = 1 - 0.5 = 0.5

Margin of error = E = 3% = 0.03

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 = (  Z_/2 / E)² * * (1 - )

= (1.96 /0.03)² * 0.5 * 0.5

= 1067.11 = 1068

Sample size = n = 1068

Option e) is correct .