🔢 Math Calculator

📐 How It Works

Calculates the arithmetic mean — the sum of all values divided by the number of values. The most common measure of central tendency.

🔢 Worked Examples

• Mean of [2, 4, 6, 8, 10] = 30/5 = 6
• Weighted: 70% exam + 30% homework → 0.7×85 + 0.3×90 = 86.5
• Running average after adding 95 to [80, 90]: (80+90+95)/3 = 88.3

📋 Common Use Cases

• Grade point average (GPA) calculation
• Stock price moving averages (7-day, 30-day)
• Quality control — average defect rate
• Sports statistics — batting average, scoring average

💡 Did You Know?

The arithmetic mean is sensitive to outliers. Bill Gates walking into a room of 100 people raises the average net worth by millions, while the median barely changes. That's why median income is a better measure than mean income.

⚠️ Common Mistake

Averaging averages: if Group A (10 people) averages 80 and Group B (100 people) averages 70, the combined average is NOT 75. It is (10×80 + 100×70)/110 ≈ 70.9.