This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
Most commonly used statistical average - 
Select and explain. 
A. Mean, B. Median, C. Mode, D. None
A: Mean
Answer: A: Mean 
Explanation: Arithmetic mean 

It is the most commonly used statistical average.
To calculate mean, add up the values of all individual observation and then divide by the number of observations.
The process of adding together is called summation and is denoted by the sign ∑ or S.
The individual observation is denoted by ŋ
The mean is denoted by the sign X.
Example :-