9. Sample size for an interval estimate of a population proportion

Suppose academic researchers are conducting a study to estimate the proportion of firms with a chief marketing officer in their top management teams. The project manager desires a 0.10 margin of error at 90% confidence. The planning value for p is p* = 0.4.

Use the following Distributions tool to help you answer the question that follows.

To satisfy the desired margin of error, a sample size no smaller than is needed.