Here is an example of how the math works assuming you chose a 90 confidence level 6 standard deviation and a margin of error confidence interval of - 4. Some researchers follow a statistical formula to calculate the sample size. 196 for 95 confidence level p percentage picking a choice expressed as decimal.
As such the determination of the appropriate sample size is one of the recurrent problems in statistical analysis.
Necessary Sample Size Z-score2 StdDev 1-StdDev margin of error2. If we are using three independent variables then a clear rule would be to have a minimum sample size of 30. Calculation of the Sample Size. The calculation of the sample size is as shown below.
