I have been tinkering with LibreOffice Calc and read a book on analysing company data. I came across some interesting statistics functions beyond what most schools teach. Most of them give you a basic introduction on the SUM-Fuction, IF-Fuction etc.
I would like to draw your attention on the RANK-Fuction which can be used to analyse the importance of a product group in terms of sales. I have written down an example on how to use this function which shows two products sold to 11 customers and what amount of turnover they make. These sales figures are then put through the RANK-fuction.
I don't know if Postgres has a similar fuction built in but it does have some statistics functions which can be used right on the database-server side.
I am assuming this is also the way amazon.com determines which rank a particular book has in.
Feel free to grab the demo sheet from http://www.tapwag.org/Rank_Demo.ods
This fuction determines if a two data sets are interrelated. As an example you might run a company which has different sales outlets (e.g. Apple stores) which have a certain size and produce a certain amount of turnover. You might as yourself if the size of the store and the turnover are interrelated. In short words: If I create bigger stores, will they produce more turnover taking these two factors into account?
The Syntax is quite simple: =PEARSON(Matrix1;Matrix2)
Again, I have set up a demo sheet at http://www.tapwag.org/Pearson_Demo.ods