You notice that a formula is missing on three worksheets. You will insert the formula simultaneously. With the worksheets still grouped, in cell E21, enter a formula to subtract the Grand Total Percentage Sold from 1. Apply Bold to the cell. Ungroup the worksheets. The Totals worksheet contains summary data. You will insert a hyperlink to the number of seats sold in each respective worksheet. On the Totals worksheet, in cell A5, insert a hyperlink to cell C21 in the Friday worksheet with the ScreenTip text Friday. In cell A6, insert a hyperlink to cell C21 in the Saturday worksheet with the ScreenTip text Saturday. In cell A7, insert a hyperlink to cell C21 in the Sunday worksheet with the Screen Tip text Sunday. Test the hyperlinks to ensure the work correctly. Now you are ready to insert a formula with a reference to the number of seats sold for Friday's performance. In cell B5, insert a formula with a 3-D reference to cell C21 in the Friday worksheet. Now you are ready to insert a formula with a reference to the number of seats sold for Saturday's performance. In cell B6, insert a formula with a 3-D reference to cell C21 in the Saturday worksheet