292 Chapter 10 Perform Calculations on Data
Relative references are useful when you summarize rows of data and want to use the same
formula for each row. As an example, suppose you have a worksheet with two columns of
data, labeled SalePrice and Rate, and you want to calculate your sales representative’s com-
mission by multiplying the two values in a row. To calculate the commission for the first
sale, you would type the formula =B4*C4 in cell D4.The formula is displayed in the formula bar, and its result is displayed in the cell.Selecting cell D4 and dragging the fill handle until it covers cells D4:D9 copies the for-
mula from cell D4 into each of the other cells. Because you created the formula using
relative references, Excel updates each cell’s formula to reflect its position relative to the
starting cell (in this case, cell D4.) The formula in cell D9, for example, is =B9*C9.