Social Statistics for a Diverse Society
Eighth Edition
Chapter Main Points and Learning Objectives
Chapter main points
- The goal of most research is to find population parameters. The major objective of sampling theory and statistical inference is to provide estimates of unknown parameters from sample statistics.
- Researchers make point estimates and interval estimates. Point estimates are sample statistics used to estimate the exact value of a population parameter. Interval estimates are ranges of values within which the population parameter may fall.
- Confidence intervals can be used to estimate population parameters such as means or proportions. Their accuracy is defined with the confidence level. The most common confidence levels are 90%, 95%, and 99%.
- To establish a confidence interval for a mean or a proportion, add or subtract from the mean or the proportion the product of the standard error and the Z value corresponding to the confidence level.
Learning objectives
- Explain the concepts of estimation, point estimates, confidence level, and confidence interval
- Calculate and interpret confidence intervals for means
- Describe the concept of risk and how to reduce it
- Calculate and interpret confidence intervals for proportion