If n = 600 and ˆ p p ^ (p-hat) = 0.85, construct a 99% confidence interval. Give your answers to three decimals

Answer 1

phat +/- Z_.005*Sqrt(phat*(1-phat)/n) Z_{.005 =} InvNorm(.005,0,1,RIGHT) = 2.5758

.85 +/- 2.5758*sqrt(.85*.15/600)

(0.812, 0.888)

We are 99% confident that the true proportion is between 0.812 and 0.888