5. Estimating Proportions, Ratios, and Subpopulation Means

  1. Steven K. Thompson

Published Online: 10 FEB 2012

DOI: 10.1002/9781118162934.ch5

Sampling, Third Edition

Sampling, Third Edition

How to Cite

Thompson, S. K. (2012) Estimating Proportions, Ratios, and Subpopulation Means, in Sampling, Third Edition, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118162934.ch5

Author Information

  1. Simon Fraser University, Canada

Publication History

  1. Published Online: 10 FEB 2012
  2. Published Print: 23 FEB 2012

Book Series:

  1. Wiley Series in Probability and Statistics

Book Series Editors:

  1. Walter A. Shewhart and
  2. Samuel S. Wilks

ISBN Information

Print ISBN: 9780470402313

Online ISBN: 9781118162934



  • confidence interval;
  • estimation method;
  • propositions;
  • ratio estimator;
  • subpopulation means


To estimate a population proportion using simple random sampling, the usual methods associated with estimating a population mean, forming confidence intervals based on the normal approximation and determining sample size could be used. However, several special features are worth noting: (1) the formulas simplify considerably with attribute data; (2) exact confidence intervals are possible; and (3) a sample size sufficient for a desired absolute precision may be chosen without any information on population parameters. In this chapter a section on estimating a ratio is included mainly to distinguish that situation from estimating a proportion. The chapter talks about the estimating proportions, mean, and totals for subpopulations because when the simple random sample is selected from the whole population, the sample size for the subpopulation is a random variable.

Controlled Vocabulary Terms

confidence interval; ratio distribution; Ratio estimator