I am trying to get the weighted avg of percentages in excel. I have followed multiple mathematical examples and excel examples all over the web and I still have not got a clear answer when you have two factors or criteria that make up the percentage.
1.) I am calculating Growth Rate from month to month. So each month has a different growth rate or percentage.
2.) So I have 2 Columns. 'START'(A) to indicate total number of people at start of the month and 'END' (B) to indicate the total number of people at the end of the month.
3.) A and B = Growth Rate or percentage which is in Column C. The formula used to calculate the growth rate is (A-B)/A
How do I get the weighted average? What is the correct math to use?
Just for the fun of answering this question lingering in the dark almost forgotten after 5 years. ;)
Here is an example in Python https://hinty.io/rivashchenko/weighted-average-python/
Your limited data example of growth percentages, could be weighed by the values from the start or end column. So weighing by the start values gives this result
picture of excel file
This is a youtube video about weighted mean https://www.youtube.com/watch?app=desktop&v=8mhVQU-ZX8I