WeightedMean
The weighted mean of the selection based on a specified weighting column.
It is a mean where some values contribute more than others.
Weighted means can help with decisions where some considerations are more important than others.
The formula:
In other words: multiply each weight w by its matching value x, sum that all up, and divide by the sum of weights.
Sample 1:
Sam wants to buy a new camera, and decides on the following rating system:

Image Quality 50%

Battery Life 30%

Zoom Range 20%
Based on reviews the Cony camera gets 8 (out of 10) for Image Quality, 6 for Battery Life and 7 for Zoom Range
The Sanon camera gets 9 for Image Quality, 4 for Battery Life and 6 for Zoom Range
Which camera is best?
Cony: (50/100) × 8 + (30/100) × 6 + (20/100) × 7 = 4 + 1.8 + 1.4 = 7.2
Sanon: (50/100) × 9 + (30/100) × 4 + (20/100) × 6 = 4.5 + 1.2 + 1.2 = 6.9
Sam decides to buy the Cony.
Sample 2:
A company sells Mango products with the following Revenue breakdown for the current year
Products 
Revenue 
Mango Tarts 
45,000 
Mango Juice 
297,000 
Dried Mangoes 
975,000 
Total 
1,317,000 
Revenue values per product
The Company posted an increase in revenue from the previous year with the following Percentage Change:
Products 
Revenue Percentage Change 
Mango Tarts 
50% 
Mango Juice 
10% 
Dried Mangoes 
30% 
Revenue percentage change values
Compute for the allover revenue change percent:
((50/100) x 45,000 + (10/100) x 297,000 + (30/100) x 975,000) / 1,317,000
or
(22,500 + 29,700 + 292,500) / 1,317,000 = .26 or 26%
NOTE: Weighted columns such as Weighted Mean, Weighted Harmonic Mean, and Weighted Sum have the Weight dropdown list enabled.