Write the word or phrase that best completes each statement or answers the question.
-Describe the steps involved in using the z-interval procedure to obtain a confidence interval for the population mean when $\sigma$ is known. Include a description of the preliminary data analysis. Why is preliminary data analysis needed?

Question

Write the word or phrase that best completes each statement or answers the question.
-Describe the steps involved in using the z-interval procedure to obtain a confidence interval for the population mean when $\sigma$  is known. Include a description of the preliminary data analysis. Why is preliminary data analysis needed?

Quizplus · Accepted Answer

The Answer is Preliminary data analysis is needed to verify that the conditions for using the z-interval procedure are satisfied. This involves constructing a graph such as a normal probability plot, a boxplot, a stem-and-leaf plot, or a histogram and examining the data. If it is reasonable to proceed, calculate the sample mean and obtain the confidence interval by using the formula

\bar { x } = z _ { \alpha / 2 } \frac { \sigma } { \sqrt { n } } ext { to } \bar { x } + z _ { \alpha / 2 } \frac { \sigma } { \sqrt { n } }

Write the Word or Phrase That Best Completes Each Statement σ\sigmaσ

Write the Word or Phrase That Best Completes Each Statement $\sigma$