After completing this ubit, the student will be able to use the Goal Seek Tool of EXCEL to solve technical problems.
| Go
back to the example problem that calculated the
area of a circle. Type in different values for D to see if you can get A to be 67 in2. 9 in gets pretty close. To get closer, try working up from 9.1 in. 9.2 in is the answer in example 8 of the Algebra section. This solution did not require the algebraic step of solving for the unknown variable before entering the GIVEN data. |
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The EXCEL package contains a Goal Seek solution method, which does what you just did. It tries lots of numbers in one cell to get the desired value in another cell. That value is the solution.
| Goal
Seek is on the Tools menu. The dialog box has
three entries: The cell containing the formula
which calculates the desired value, e.g. area
(click it), the desired value (type it), and the cell containing the value to FIND (click it). |
 |
This spreadsheet calculates the area of a trapezoid. The necessary area is 200 in2. The lengths of the base and one side are designated. The problem is to find the second side length. It is set up to allow Goal Seek to FIND the value of HR. When the sheet is prepared as below, select Goal Seek from the Tools menu.
| Set
cell---Click the cell below
"A" To value---Type 200 By changing cell---Click cell below HR Click OK |
|
Goal Seek will end with the solution value under HR and the calculated value under A.
EXAMPLE PROBLEM SOLUTION
The initial value for A is zero because the initial value of W is zero. A=L*W
