Revised 9/2/99                                 Regression and Excel

I. Scatterplots

  A. Position X data column before Y data.

  B. Select X and Y column without labels.  If X and Y are not adjacent, hold CONTROL while
      selecting second column.

  C. Click CHART WIZARD.
       1. Under Standard Types select XY (Scatter) for the Chart type.  Then under chart sub-type
           select the first (top) box that only contains data points.  Click NEXT.
       2. Check that Data Range is correct in the next window.  The name after the = sign and
           before the ! is the name of the worksheet that contains the data.  Check also that columns
           is checked if your data is in columns rather than rows.  Click on the Series tab and check
           that the X and Y variables are not confused.  You can also name the chart in the Name: slot.
           When you have everything set here, click NEXT.
       3. In this window you can label the axes under the Titles tab.  Play around with the other tabs
           and notice how they change the chart and inform the reader.  Click NEXT.
       4. Tell Excel where to place the chart.  Click FINISH.

  D. Editing Chart
       1. Click inside chart.  Border should appear with 8 small black squares around the outside.
       2. To change Axis Scale: Click desired axis.  Click right button and choose FORMAT Axis.
           Experiment with different tabs and choices but most useful is probably Scale.  You can
            change minimum and maximum values on the axes to avoid bunching of data with large
            amounts of white space.
       3. Change Size: To move a particular side, click and hold on small black square on this side
           (two-pointed arrow appears).  Drag to desired size. To move two adjacent sides, perform
           similar move with square in corner.  To move entire diagram, click and hold inside box
           (not the chart itself) as you drag to desired position.  Four-pointed arrow appears.
 

 II. Regression Output

  A. Simple Regression
        1. Under TOOLS menu, select DATA ANALYSIS.  Choose REGRESSION.  Click OK.
        2. Fill in Regression Dialog Box.
            a. Type or select Y and X ranges.  Indicate whether labels are included.  Check if want to
                force line through origin (this is not usually the case for us).
            b. Position output on new page--give it a name, Y=f(X).
            d. Selected desired residual analyses.  Select LINE FIT to show results on scatterplot.

  B. Editing Charts:  See Scatterplots

  C. Multiple Regression
       1. Position independent variable (Xs) into adjacent columns.
       2. Repeat rules for simple regression, but use range of X values rather than column, when
           defining position of independent variables.

  D. Correlation
       1. Arrange variables of interest in adjacent columns.
       2. Under TOOLS menu, select DATA ANALYSIS.  Choose CORRELATION.  Click OK.

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