Question

A Pew Internet poll asked cell phone owners about how they used their cell phones. One question asked whether or not during the past 30 days they had used their phone while in a store to call a friend or family member for advice about a purchase they were considering. The poll surveyed 1008 adults living in the United States by telephone. Of these, 469 responded that they had used their cell phone while in a store within the last 30 days to call a friend or family member for advice about a purchase they were considering. You are planning a survey similar to the one about cell phone use described above. You will report your results with a large-sample confidence interval. How large a sample do you need to be sure that the margin of error will not be greater than 0.04 at 95% confidence?

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Answer 1