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OpenStax, Statistics §8.3 A Population Proportion · Exercise 45 · Statistics · Confidence intervals

A Population Proportion · Exercise 45

On May 23, 2013, a polling group reported that of the 1,005 people surveyed, 76 percent of U.S. workers believe that they will continue working past retirement age. The confidence level for this study was reported at 95 percent with a ±3 percent margin of error.

(a) Determine the estimated proportion from the sample.
(b) Determine the sample size.
(c) Identify CL and α.
(d) Calculate the error bound based on the information provided.
(e) Compare the error bound in Part d to the margin of error reported by the polling group. Explain any differences between the values.
(f) Create a confidence interval for the results of this study.
(g) A reporter is covering the release of this study for a local news station. How should she explain the confidence interval to her audience?

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OpenStax, Statistics · §8.3 A Population Proportion · Exercise 45

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