Weighted Average is an average that takes into account the proportional relevance of each component, rather than treating each component equally.
Weightings are the equivalent of having that many like items with the same value involved in the average.
Example:
Grades are often computed using a weighted average.
Suppose that homework counts 10%, quizzes 20%, and tests 70%.
If Peter has a homework grade of 82%, a quiz grade of 78%, and a test grade of 91%,
then Peter overall grade = (0.10)(82) + (0.20)(78) + (0.70)(91) = 87.5 %