(Assuming first cell is A1)
The dollar signs are important. Get it right in the first cell and then drag the formula down. Those cells you referenced with dollar signs in front of the row or the column won't change as you drag the formula down.
And since I'm assuming you don't just have 3 records, you will want to change the ranges in your first formula before dragging down.
Also, by clicking in the formula bar, it will highlight the color of the part of the formula assocaited with which part of the range.