Average Calculator

* SD = standard deviation

Weighted average calculator ►

Average calculation

The average (arithmetic mean) is equal to the sum of the n numbers divided by n:

Average = sum / count = (a1+a2+...+an) / n

Example

The average of 1,2,5 is:

Average = (1+2+5) / 3 = 2.667

Weighted average calculator

Weight Data value

Weighted average calculation

The weighted average (x) is equal to the sum of the product of the weight (wi) times the data number (xi) divided by the sum of the weights:

weighted average


Example

Find the weighted average of class grades (with equal weight) 70,70,80,80,80,90:

Since the weight of all grades are equal, we can calculate these grades with simple average or we can cound how many times each grade apear and use weighted average.

2×70,3×80,1×90

x = (2×70+3×80+1×90) / (2+3+1) = 470 / 6 = 78.33333

 

Weighted average calculator ►


See also

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