OpenStax, Introductory Business Statistics 2e §8.3 A Confidence Interval for A Population Proportion · Example 1 · Statistics · Confidence intervals

A Confidence Interval for A Population Proportion · Example 1

Suppose that a market research firm is hired to estimate the percent of adults living in a large city who have smartphones. Five hundred randomly selected adult residents in this city are surveyed to determine whether they have smartphones. Of the 500 people sampled, 421 responded yes - they own smartphones. Using a 95% confidence level, compute a confidence interval estimate for the true proportion of adult residents of this city who have smartphones.

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OpenStax, Introductory Business Statistics 2e · §8.3 A Confidence Interval for A Population Proportion · Example 1

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