This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Statistical Errors, p-value, Subject name: Social & Preventive Medicine
What will be the 95% confidence interval in a study estimated prevalence of 10% and 100 being their sample size? 
Select and explain. 
A. 16-Apr, B. 18-Feb, C. Inadequate information to calculate 95% CI, D. 13-Jul
A: 16-Apr
Answer: A: 16-Apr 
Explanation: Confidence intervals for population propoions (for 95% confidence) CI = P +- 2 SEP = P +- [?]pq/n In the given question, p = 0.10 (10%) So, q=1-p = 1- = 0.90; n= 100 CI = 0.10 +- 2 [?]0.1*0.9/100 = 0.10 +- 0.06 = 0.04, 0.16 (4%, 16%)