Using average of a column

Hi, this module is exactly what I was looking for but I hav a few questions about this.

1) How insert the result of a column (average exactly) in the node where my view is?
And use it with another different views?

2) I would like to display the average of column A, the sum of B, and the count of C? How to do this? Without displaying in 3 rows the average of A B C, the sum of A B C and the count of A B C...
because for exemple, the average of C doesn't mean anything, so I don't want to display it.

Thank a lot Karen for yours Drupal applications and explanations. It's hellp me a lot. ^^

Julien