If n=600 and p' (p-prime) = 0.82, construct a 95% confidence interval.

Question

If n=600 and p' (p-prime) = 0.82, construct a 95% confidence interval.

Give your answers to three decimals.

 < p < 

Answer 1

You may use the formula CI = [ p^' - z * √p(1-p)/n , p^' + z * √p(1-p)/n ].

The z-score for the 95% confidence interval is 1.96, and p' can be used as an estimation of p.

Therefore:

CI = [ 0.82 - 1.96 * √(0.82*0.18/600) , 0.82 + 1.96 * √(0.82*0.18/600) ] = [0.79, 0.85].