SOLUTION: A random sample of 1200 workers in a particular city found 348 workers who had donated to charity. Find a 95% confidence interval for the true percent of workers in this city who

Question 1076839: A random sample of 1200 workers in a particular city found 348 workers who had donated to charity. Find a 95% confidence interval for the true percent of workers in this city who have donated to charity.
Express your results as percents. Round to at least two decimal places.
My previous answers were 26.45%,31.55%
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
The sample mean is 0.29
one sample proportion 95% CI is 0.29 +/- 1.96*sqrt (0.29*0.71/1200)=0.29+/-1.96*0.130=+/-0.0257
(0.2643, 0.3157)
(0.26, 0.32) to two decimal places. Calculator confirms.
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