Book Image

Minitab Cookbook

By : Isaac A Newton
Book Image

Minitab Cookbook

By: Isaac A Newton

Overview of this book

Table of Contents (19 chapters)
Minitab Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Finding the sample size to estimate a mean to a given margin of error


Here, we want to obtain the sample size required to estimate a population parameter to a given margin of error. We will not use specific values but will find the number of samples required to estimate a mean with a confidence interval ±0.5 and ±1 standard deviation wide.

How to do it…

The following steps will identify the number of samples required to find an estimate of the population mean to a confidence interval of +/- 0.5 and +/-1 standard deviations wide:

  1. Go to the Stat menu, go to Power and Sample Size, and select Sample Size for Estimation….

  2. In the Parameter section, select Mean (Normal) from the dropdown.

  3. Under Planning Value, enter Standard deviation: as 1.

  4. In Margins of error for confidence intervals:, enter 0.5 and 1 (separated by a space).

  5. Click on OK.

How it works…

We are trying to find the sample size required to estimate the population mean as +/- 0.5 or 1 standard deviations. Eighteen samples would give us a confidence...