# What is the sample size required for a survey of shoppers who use credit cards?

A survey of shoppers is planned to determine what percentage use credit cards. Prior surveys suggest that 59% use credit cards. The required margin of error is 0.02 at 95% confidence. What is the minimum sample size required to assure that your sample proportion "p" will be within the required margin of error around the population proportion "p."

Use the traditional methods for testing hypotheses and show the results of all steps in the process.

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#### Solution Preview

Sample Size = (2^2*Z^2* p^.5 *(1-p)^.5)/L^2

Z= 1.65 ( FROM NORMAL Table for 95% confidence interval)

p= ...

#### Solution Summary

This solution provides calculations for the sample size, confidence interval and range.

$2.49