Calculate the mean where some values contribute more than others.
Weighted Average Result:
0.00
Sum of Products: 0 | Sum of Weights: 0
How to Calculate Weighted Average
A weighted average is a calculation that takes into account the varying degrees of importance of the numbers in a data set. Unlike a simple average where all numbers carry equal weight, a weighted average assigns a "weight" to each value.
The Weighted Average Formula
Weighted Average = (Σ (x * w)) / Σ w
x = The value of the data point.
w = The weight assigned to that value.
Σ = The sum of all values.
Real-World Examples
Example 1: School Grades
Imagine a class where your Midterm is worth 30% and your Final is worth 70%. If you scored 80 on the Midterm and 90 on the Final, a simple average would be 85. However, the weighted average is higher because the Final carries more weight:
(80 × 0.30) + (90 × 0.70) = 24 + 63 = 87.0
Example 2: Investment Portfolios
If you own two stocks, one valued at 100 shares at 50 per share and another at 200 shares at 80 per share, you use weighted average to find the average price per share across your entire position.
Why use a Weighted Average?
This method is essential when dealing with datasets where certain components are more significant than others. It is commonly used in:
Finance: Calculating the average price of shares purchased at different times.
Education: Calculating GPA or final course grades.
Accounting: Inventory valuation (Weighted Average Cost Method).
Statistics: Adjusting for demographic differences in polling data.
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function calculateWeightedAverage() {
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