Hi, Glen.
I always use combine to aggregate data. Then you could make an average block like this:
note that the "numbers" input is of type "number - multiple", i.e. a variadic input. You could also simply specify it to be a list. You can use it on any list - including samples and frequency spectrum bins - by dropping the data reporter onto the arrows:
which gets the same result:
Is that what you were looking for?