New Column Formula questionQuestion: I would like to compare dates in one column to dates in a second column that only has sporadic entries. For example, I have a lot of lab values with dates (column named "Lab Date"), but at irregular intervals, patients have a biopsy date (separate column). I would like to know what was the mean lab value ("Level") for any of the values that fall within a month preceding the biopsy date ("Bx date"). If someone could show me how to do this in the formula editor I would be grateful.
