SOLUTION: In a random sample of 380 residents of Fiction County, it was found that only 57 could correctly name the president of France. Use this information to construct a 90% confidence in

Algebra ->  Probability-and-statistics -> SOLUTION: In a random sample of 380 residents of Fiction County, it was found that only 57 could correctly name the president of France. Use this information to construct a 90% confidence in      Log On


   

Question 1186970: In a random sample of 380 residents of Fiction County, it was found that only 57 could correctly name the president of France. Use this information to construct a 90% confidence interval for p, the proportion of all residents of Fiction County who can correctly name the President of France.
Round your answers to three significant figures.
Answer: We are 90% confident that __ < p < __ .
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
p hat=57/380=0.15
90% half-interval is z(.95)*sqrt(.15*.85/380)
=1.645*0.0183
=0.0301
the interval is (0.120, 0.180)