How do I use the Goal Seek feature in Excel?

Excel's Goal Seek feature allows you to determine the input value needed to reach a desired outcome. This is useful when you know the desired result, but you're not sure what input values will achieve it. Here are the steps to use the Goal Seek feature:

1. Select the cell that contains the formula you want to change.
2. Go to the Data tab and click on What-If Analysis, then choose Goal Seek.
3. In the Set cell field, enter the cell that contains the formula you want to change.
4. In the To value field, enter the desired result of the formula.
5. In the By changing cell field, enter the cell that contains the value you want to adjust.
6. Click OK.

Excel will run a series of calculations until it finds the input value that produces the desired result. When the calculation is complete, Excel will display a dialog box with the result. You can choose to accept the new value or revert to the original value.