A confidence interval for a population mean µ with specific margin of error E and known population standard deviation σ is given by, \(n=\left(\frac{z_{\alpha / 2} \cdot \sigma}{E}\right)^{2}\). We ca...A confidence interval for a population mean µ with specific margin of error E and known population standard deviation σ is given by, \(n=\left(\frac{z_{\alpha / 2} \cdot \sigma}{E}\right)^{2}\). We can estimate σ by using a previous year’s standard deviation or a standard deviation from a similar study, a pilot sample, or by dividing the range by 4. Most of the time the margin of error = E follows the word “within” in the question, E = 100.
A confidence interval for a population mean µ with specific margin of error E and known population standard deviation σ is given by, \(n=\left(\frac{z_{\alpha / 2} \cdot \sigma}{E}\right)^{2}\). We ca...A confidence interval for a population mean µ with specific margin of error E and known population standard deviation σ is given by, \(n=\left(\frac{z_{\alpha / 2} \cdot \sigma}{E}\right)^{2}\). We can estimate σ by using a previous year’s standard deviation or a standard deviation from a similar study, a pilot sample, or by dividing the range by 4. Most of the time the margin of error = E follows the word “within” in the question, E = 100.
