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Confidence interval and sample size

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In a survey, 200 people were asked to identify their major source of news information; 110 stated that their major source was television news.

a. Construct a 95% confidence interval for the proportion of people in the population who consider television their major source of news information.

b. Determine how large a sample would be necessary to estimate the population proportion with a margin of error of .05 at 95% confidence.

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This shows how to construct a confidence interval and determine sample size.

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