Arithmetic Mean

The arithmetic mean is the simplest and most intuitive average we encounter — the number that lies exactly midway between two extremes. For any two numbers $a$ and $b$, their arithmetic mean is simply $\frac{a+b}{2}$, the value that balances them on the number line. This idea extends naturally to more than two numbers: the arithmetic mean of a set of $n$ observations is their sum divided by $n$, giving a single representative value around which the data clusters. Understanding this concept is the foundation for co …