Obviously, I'm not going to deal with the average function, that seems straightforward enough. This article and following articles will be about some other averages:
Weighted mean, Weighted harmonic mean, Quadratic mean, Winsor mean, Truncated mean, Mean of Angles, and so on and so forth. I didn't know there were that many means, so it's gonna be fun figuring some of them out. As I already pointed out in previous articles, I'm not a mathematician, so I'm learning this stuff as I write it.
Let's start with the Weighted mean.
The formula on Wikipedia looks like this:
Fortuntately, I had the chance of learning to read these syntaxes when I wrote the articles on trendlines. So, it's going to be just a little bit easier.
Basically, it's just going to be adding up a bunch of multiplications and dividing it again. Lets get a bunch of numbers:
Our starting table is this one -- as usual, I'm taking eFashion to start from:
We're interested in the weighted average of the Unit Price. The average is 165.80 and the median would be:165.05.
First, we multiply Quantity sold and unit price and we add them up.
In a column to the right, I'm adding =[Quantity sold]*[Sold at (unit price)]
Nice. Next, we divide that big number by the total of the quantities:
=sum([Quantity sold]*[Sold at (unit price)])/sum([Quantity sold])
This results in:
Our weighted mean is: 163
More means coming up.