As described in my previous question, I am currently conducting an epidemiological study in a health institution where we investigate the prevalence of Corona virus infections by measuring the existence of antibodies.

We now have the results of our study and are looking at 424 participants in a population of 785 individuals and a prevalence of 2.8% (12 individuals). As posted in my question before, I used the formula from Niang 1 to calculate the necessary sample size for a 95% confidence interval and arrived at 618.

Now to my question: Since we only have 424 participants, I guess that we will not be able to extrapolate this data for the whole population? Or is there a way to do so, after all? Thank you for your guidance!

1 NAING, L., WINN, T. & RUSLI, B. 2006. Practical issues in calculating the sample size for prevalence studies. Archives of orofacial Sciences, 1, 9-14.