SOLUTION: A survey of 280 homeless persons showed that 63 were veterans. Current statisticians believe that 20% of homeless people are veterans. Does a 90% confidence interval suggest that t

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Question 1155668: A survey of 280 homeless persons showed that 63 were veterans. Current statisticians believe that 20% of homeless people are veterans. Does a 90% confidence interval suggest that the proportion of homeless people who are veterans is really more than 20%?

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
point estimate is 63/280=0.225
90%CI is z0.95*sqrt(p*(1-p)/200)=1.645*sqrt(0.225*0.775)/200)=
=0.0486 (rounded here)
Add and subtract that from mean
interval is (0.176, 0.274)
Because the interval contains 0.2, we cannot conclude that the true proportion is more than 0.20. Every estimate in the interval is potentially the right one with 90% confidence.