How do you place a bottom double border on the selected cells?

To place a bottom double border on selected cells in Excel, first highlight the desired cells. Then, go to the "Home" tab, click on the "Borders" drop-down menu in the Font group, and select "More Borders." In the Format Cells dialog, choose the "Outline" and "Inside" options, select the double line style under "Style," and apply it to the bottom border before clicking "OK."