SOLUTION: From a large number of actuarial exam scores, a random sample of 250 scores is selected, and it is found that 170 of these 250 are passing scores. Based on this sample, find a 95%

Question 1159926: From a large number of actuarial exam scores, a random sample of 250 scores is selected, and it is found that 170 of these 250 are passing scores. Based on this sample, find a 95% confidence interval for the proportion of all scores that are passing.
Carry your intermediate computations to at least three decimal places. Round your answers to two decimal places.
What is the lower limit of the 95% confidence interval?
What is the upper limit of the 95% confidence interval?

Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
The point estimate or p hat is 0.68
the half-interval is z(0.975)*sqrt (p*(1-p)/n)=1.96* sqrt (0.68*0.32/250)=0.0578 or 0.06
The 95% CI of the proportion parameter is (0.62, 0.74)
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