s = \frac{13 + 14 + 15}{2} = 21

Thu, 16 Apr 2026 15:36:49 +0000

Understanding the Calculation: Why s = rac{13 + 14 + 15}{3} = 21 When solving equations and evaluating averages, one common expression encountered is $$
s = rac{13 + 14 + 15}{3} = 21
$$ But what exactly does this mean? Why is this sum divided by 3 to give 21? Let’s explore this simple yet powerful calculation.