weighted arithmetic mean
We will often see that is the calculation of GPA. so, GPA calculation we need to use a weighted arithmetic mean method.
forasmuch each subject that we study is of equal importance. Or to make it easier to understand, each subject has different credits.
so, if we use arithmetic mean method. the result will be tilted to the subjects with many credits.
The formula used for weighted averages
the sum of (the value x the weights) / sum of the weighted values
Subject A: Grade 3 (3 credits)
Subject ฺB: Grade 4 (1 credits)
Subject C: Grade 4 (2 credits)
Subject D: Grade 3 (3 credits)
If we use an arithmetic mean method.
Data sum is (3+4+4+3) = 14
The result is 14 / 4 = 3.50
But, if we use a weighted arithmetic mean method.
Data sum is (3x3 + 4x1 + 4x2 + 3x3) = 30
Sum of the weighted values is (3+1+2+3) = 9
The result is 30 / 9 = 3.33
So, the GPA for this term is 3.33