## zaterdag, januari 19, 2013

### Calculating averages in Business Objects

Time for some averages.

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.

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.

Peter