1.leaf cell value> = <NEW Value> / COUNT(leaf cells that are contained IN <tuple>)
2.leaf cell value> = < NEW Value> * Weight_Expression
3.<leaf cell value> = <leaf cell value> + (<NEW VALUE > - <existing value>) / COUNT(leaf cells contained IN <tuple>)
4.leaf cell value> = <leaf cell value> + (<NEW Value> - <existing value>) * Weight_Expression