Final answer:
To determine if a worksheet is grouped, check for the [Group] indication in the title bar of the spreadsheet program.
Step-by-step explanation:
To determine if a worksheet is grouped in a spreadsheet program like Microsoft Excel, you should look for the indication that [Group] displays in the title bar. When worksheets are grouped, you will see the word [Group] appended to the name of the workbook in the title bar of the window. This is a clear indicator that you have more than one worksheet selected and that they are grouped. The tabs of grouped worksheets usually change color as well, but the specific color can vary depending on the software version or theme and is not always yellow. Therefore, the most reliable method is to check for the [Group] indication in the title bar.