Select the chart
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Click the Layout tab under Chart Tools.
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Click Chart Titles button
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Click 'None' to hide the chart title.
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Click 'Centered Overlay Title' to insert a title on the chart without resizing it.
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Click 'Above Chart' to position the chart title at the top of the chart and resize it.
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Click More Title Options to set custom chart title options.
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Double-click the text box to place the insertion point
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Then modify the text.
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