Creating Combination (Overlay) Charts
Sometimes you'll find that a chart with multiple data series becomes more intelligible if you plot one or more series in a style that contrasts with the other series. For example, you might want to plot one series as columns and another as a line. To create this kind of overlay chart, first see if the combination you're looking for is already represented on the Custom Types tab of the Chart Wizard's Step 1 dialog box. If it's not, follow these steps
Create the chart using one of the standard chart types.
On the finished chart, right-click the data series that you want to appear in a contrasting style.
From the shortcut menu, choose Chart Type.
Select the style you want, and select the Apply To Selection check ...