The formula does not cover finite population. Use the sample size formula Plug in your Z-score standard of deviation and confidence interval into the sample size calculator or use this sample size formula to work it out yourself. If we are using three independent variables then a clear rule would be to have a minimum sample.
If we are using three independent variables then a clear rule would be to have a minimum sample.
N z 2 p 1 - p e 2 where z 1645 for a confidence level a of 90 p proportion expressed as a decimal e margin of error. N z 2 p 1 - p e 2 where z 1645 for a confidence level a of 90 p proportion expressed as a decimal e margin of error. This equation is for an unknown population size or a very large population size. Z 1645 p 05 e 004.