Use the Sample Size Calculator to determine the sample size you need in order to get results that reflect the target population as precisely as needed. You can also find the level of precision you have in an existing sample. The site also describes terms you need to know to understand confidence intervals and what they mean.
Internet Explorer 3.0 or later or Netscape 3.0 or later or a compatible browser
Source Code Available:
Source Code Not Available
Intended User Role:
Free for All