# Chapter 7 - Estimates and Sample Sizes - 7-3 Estimating a Population Mean - Basic Skills and Concepts - Page 360: 28

753. A major problem can be not being able to get exact results by questioning people.

#### Work Step by Step

$\alpha=1-0.95=0.05.$ Using the table: $z_{\alpha/2}=z_{0.025}=1.96.$ Hence the sample size:$\left (\frac{z_{\alpha/2}\cdot \sigma}{E}\right)^2=\left (\frac{1.96\cdot 210}{6}\right)^2\approx753$. A major problem can be not being able to get exact results by questioning people.

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.