Weighted Average

Definition

Weighted Average in plain English

A weighted average is just an average where some numbers count more than others because they represent more stuff. Say your class grade is 80% homework and 20% final exam, a 90 on homework matters more than a 90 on the final, so you can't just add them and divide by two; you multiply each by how much it 'weighs' first. In math terms, if 8 items average 90 and 2 items average 40, the true average leans toward 90 because there are more of them: (8×90 + 2×40)/(10) = 80. The big idea: whenever groups have different sizes or importance, the combined average is pulled toward the bigger or heavier group.

Learn these first

• Absolute Value
• Arithmetic Mean

Related GMAT terms

• Absolute Value
• Arithmetic Mean
• Composite Number
• Discrete Data
• Discriminant
• Domain
• Exponent
• Factorial
• Greatest Common Divisor (GCD)
• Independent Events