When you have more than one series you can have a different chart type for each series. In this example I'll show you how to change one series to a histogram. You will also see how to add a separate 'Y' axis for each series.

Right Click on the series you want to change. Then select the type of chart you want to apply to this series. I've chosen a type 'column'.   Roll your mouse over the image to see what happens.

If you want a different scale for the second series, go to the 'Chart Options' menu and select 'Axes'. In this example I am adding a 'Y' axis.

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