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Sample size for estimating a population proportion

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The manager of a department store wants to determine what proportion of people who enter the store use the store's credit cards for their purchases. What size sample should he take so that at 95% confidence the error will not be more than 6%?

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Solution Summary

This solution shows how to find the sample size necessary to construct a confidence interval within a specific margin of error and having a specific level of confidence.

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In this problem, we want to use the sample proportion, to estimate the population proportion. We want to be 95% confident that the difference between the estimate and the actual value of the population proportion is at most 0.06 in ...

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