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What sample size is necessary?

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An automobile dealership plans to conduct a survey to determine what proportion of new-car buyers continue to have their cars serviced at the dealership after the warranty period ends. It estimates that 30 percent of customers do so. It wants the results of its survey to be accurate within 5 percent, and it wants to be 95 percent confident of the results. What sample size is necessary?

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Solution Summary

Provides steps necessary to determine the sample size necessary.

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The excel file solution is attached.

The estimated proportion is p = 30% = 0.30

q = 1 ...

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