Sometimes all scores are not the same, which can be either an advantage or a disadvantage, depending on which scores count more. A weighted average score takes different scores, or grades, with assigned weights, or percentages. A common example of a weighted average score is the grade for a class that has different percentage points for homework, participation and test grades. Calculation of a weighted average score can show you what scores you have and what scores you need to receive.
Multiply the scores with their respective percentages or weights. For example, you have one score of 70 that is 25 percent of your weighted score, a score of 85 that is another 25 percent and a score of 90 that is 50 percent. Multiply 70 by 25 to get 1,750, 85 by 25 to get 2,125 and 90 by 50 to get 4,500.
Add the products from Step 1. For this example, 1,750 plus 2,125 equals 3,875, and 3,875 plus 4,500 equals 8,375.
Divide that sum by the weighted amount. For this example, the weighted amount is 100 percent, so dividing 8,375 by 100 results in 83.75.
Things You Will Need
- "Basic Math and Pre-algebra"; Jerry Bobrow; 1995
- Purple Math: How Do I Compute My Weighted Grade?
- Stockbyte/Stockbyte/Getty Images