This is a genuine project, Any decent Postgresql coder should be able to complete it fairly quickly.
Basically it requires a filtered dataset or table to be passed into a Postgresql Function.
The function needs to process the data into an array or some other suitable data structure (I don't care), adding a list of values together to produce an average, and inserting the result into a SPECIFIC output row that has been specifically selected. (Please no clever ass 4 page Sql-queries, with execution plans bigger than the nation-debt of Greece), I prefer a function/procedure so that it can be modified/expanded as a separate job
Quoting requirement , Add the following to your quote to prove you have fully READ this job:
"I am not moron and have read the project requirements"
The full specification and example case+ example CSV datafile will be supplied ONLY to non-time wasters.
I normally work on Oracle databases, so there should be little problem with technical communications.