SOLUTION: In 2009, a consulting firm surveyed a random sample of 700 U.S. businesses and found that 28% of them were owned by women. Create a 90% confidence interval for the true proport

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Question 1100566: In 2009, a consulting firm surveyed a random sample of 700 U.S. businesses and found that 28% of them were owned by women.
Create a 90% confidence interval for the true proportion of U.S. businesses that are owned by women.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
In 2009, a consulting firm surveyed a random sample of 700 U.S. businesses and found that 28% of them were owned by women.
Create a 90% confidence interval for the true proportion of U.S. businesses that are owned by women.
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sample proportion:: 0.28
ME = z*sqrt(pq/n) = 1.645*sqrt[0.28*0.72/700) = 0.0279
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90% CI: 0.28-0.0279 < p < 0.28+0.0279
90% CI: 0.2521 < p < 0.3079
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Cheers,
Stan H.
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