Youll then be able to use a sample size formula to bring everything together and sample confidently knowing that there is a high probability that your survey is statistically. Dummies has always stood for taking on complex concepts and making them easy to understand. SS fracZ2P1-PC2 Where SS Sample Size.
Can be solved for n yielding n 4 W2 1 B2 where B is the error bound on the estimate ie the estimate is usually given as within B.
In other words if an investigation is too small then it will not detect results that are in fact important. In our earlier example if there were just 1000 households in the target population we would calculate. Sample size formula is. Calculating sample size one would use a standard formula for time to failure and select as the candidate sample size the larger of the sizes required to achieve the desired power for example 80 percentfor each of the two endpoints.