Conditional formatting is commonly used in Microsoft Excel to apply a formatting style according to a set condition by the author, for example 'for values greater than cell 11B the color of the cell should be red'.
When you want to create changes in the visual format of your data, you should use this function. Thus, Chuck should use the steps outlined in (C) Styles, Conditional Formatting, Highlight Cells Rules, Greater Than, select row 19, Custom Format, Bold to achieve his goal.