# 4. Sample Size

Published Online: 10 FEB 2012

DOI: 10.1002/9781118162934.ch4

Copyright © 2012 John Wiley & Sons, Inc.

Book Title

## Sampling, Third Edition

Additional Information

#### How to Cite

Thompson, S. K. (2012) Sample Size, in Sampling, Third Edition, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118162934.ch4

#### Publication History

- Published Online: 10 FEB 2012
- Published Print: 23 FEB 2012

#### Book Series:

#### Book Series Editors:

- Walter A. Shewhart and
- Samuel S. Wilks

#### ISBN Information

Print ISBN: 9780470402313

Online ISBN: 9781118162934

- Summary
- Chapter

### Keywords:

- population mean;
- random sampling;
- relative precision;
- sample size

### Summary

This chapter first discusses sample size for estimating a population mean. With simple random sampling, the sample mean is an unbiased estimator of the population mean. The chapter then describes estimation of a population total using sample size. A bothersome aspect of sample size formulas is that they depend on the population variance, which generally is unknown. In practice, one may be able to estimate the population variance using a sample variance from past data from the same or a similar population. Finally, the chapter discusses sample size for relative precision.

#### Controlled Vocabulary Terms

mean; random sampling; Sample size; variance