It is critical to understand that different study designs need different methods of sample size estimation. If N100 then the corrected sample size would be 18600285 6526 or 66. In practice the sample size used in a study is usually determined based on the cost time or convenience of collecting the data and.
This equation is for an unknown population size or a very large population size.
In order to estimate the sample size we need approximate values of p 1 and p 2. Z is the z score. 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. For the Poisson mean length 1.