Microsoft Office Tutorials and References
In Depth Information
Precision and multiple solutions
5. Click OK, or press Enter. Excel displays the Goal Seek Status dialog box shown in
Figure 18-21. The answer you are looking for appears in the cell specified in the By
Changing Cell box.
Figure 18-21 The Goal Seek Status dialog box informs you when Excel finds a solution.
6. To enter this value on the worksheet, click OK in the Goal Seek Status dialog box.
To restore the value that was in the changing cell before you used the Goal Seek
command, click Cancel.
Excel uses an iterative technique to perform goal seeking. It tries one value after another
for the variable cell specified in the By Changing Cell box until it arrives at the solution you
requested. Excel solves the mortgage problem we just looked at quickly. Other problems
might take longer, and some might not be solvable at all.
While Excel is working on a complex goal-seeking problem, you can click Pause in the Goal
Seek Status dialog box to interrupt the calculation, and then click Step to display the result
of each successive iteration. A Continue button appears in the dialog box if you are solving
a problem in this stepwise fashion. To resume full-speed goal seeking, click Continue.
Precision and multiple solutions
Suppose you enter the formula =A2^2 in cell A1 of a blank worksheet (the caret symbol
indicates that the number following it is an exponent) and then use the Goal Seek
command to find the value of A2 that will make A1 equal to 4. (In other words, in the Goal
Seek dialog box, type \$A\$1 in the Set Cell box, 4 in the To Value box, and \$A\$2 in the By
Changing Cell box.) The result might be surprising. Excel seems to be telling you that the
closest value it can find to the square root of 4 is 2.000023.
By default, the Goal Seek command stops when it has either performed 100 iterations (trial
solutions) or found an answer that comes to within 0.001 of your specified target value. If
you need greater precision than this, you can change the default limits by clicking the File
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