To calculate weighted average, first find the weight of each number you're working with. For example, let's say you're trying to find the weighted average of your grades in a class. You got 82 on quizzes, 90 on exams, and 76 on your term paper.
If quizzes are 20% of your grade, exams are 35%, and the final paper is 45%, percent. That means the weight of 82 is 20%, the weight of 90 is 35%, and the weight of 76 is 45%. Convert the weights into decimals by moving the decimal point two places to the left. Now you have 0.2, 0.35, and 0.45. These decimals are called weighting factors.
The next step is to multiply each number by its weighting factor. In our example, you would multiply 82 by 0.2, 90 by 0.35, and 76 by 0.45, and get 16.4, 31.5, and 34.2. Finally, add all of these products together. to find the weighted average. 16.4 plus 31.5 plus 34.2 equals 82.1.
Therefore, the weighted average of your grades is 82.1%.