range refers to the dependent variable. In our case, the Y data range from cell
A3 to cell A18. Thus we could simply type A3:A18 into the box.
Alternatively, we could select the range, pointing the mouse at A3, clicking,
holding, and dragging to cell A18. There will appear in the Input Range box
the entry $A$3:$A$18. (Do not worry about the dollar signs.) If you wish to
include the column label in cell A2, simply select the range $A$2:$A$18. Then
click on the label box. (In our example, we chose to include the label.) The
advantage of using the label is it will appear in the output statistics, making
these statistics easier to read.
The X Input Range refers to the independent variable. In our case, the
X Input Range is from cell B3 to cell B18. To input the cells for this range,
repeat the procedure described above.
Step 4: Inform the program where you want the output.The regression pro-
gram needs to be told where to put the output. This is known as the output
range. Simply type in a cell name (or point and click). The program will start
with that cell and work to the right and down. It really does not matter where
you put the output except that you do not want to put it over the data, thereby
destroying the data. Thus you should put the output either below or to the
right of the data. We specified F2 as the output range. Some programs, such as
Excel, will allow you to put the output in a separate spreadsheet.
Step 5: Run the regression. Simply click OK. For the airline example, the pro-
gram produces the output shown in Table 4A.2.Multiple Regression
Performing multiple-regression analysis involves virtually the same steps as per-
forming simple regression. Recall that the data in Table 4.4 include income
and competitors’ price as explanatory variables in addition to the airline’s own
price. The first step is to enter the income and competitive price data in
columns C and D of the spreadsheet. After calling up the regression menu, we
again enter cells A2 to A18 for the Y range. However, next we enter cells B2 to
D18 for the X range. (We designate the three columns of data by selecting the
upper left and the lower right cells of the range containing the data. All
explanatory variables must be listed in adjacent columns.) The regression pro-
gram recognizes each column of data as a separate explanatory variable. Next,
we specify the output range to begin in cell F2. Finally, we execute the regres-
sion program by clicking OK. The multiple-regression output is displayed in
Table 4A.3.184 Appendix to Chapter 4 Regression Using Spreadsheetsc04EstimatingandForecastingDemand.qxd 9/5/11 5:49 PM Page 184