Excel® 2010 Bible

Chapter 37. Analyzing Data Using Goal Seeking and Solver

IN THIS CHAPTER

What-if analysis – in reverse

Single-cell goal seeking

Introducing Solver

Solver examples

The preceding chapter discusses what-if analysis — the process of changing input cells to observe the results on other dependent cells. This chapter looks at that process from the opposite perspective: finding the value of one or more input cells that produces a desired result in a formula cell.

This chapter covers two tools: Goal Seeking and the Solver add-in.

37.1. What-If Analysis, in Reverse

Consider the following what-if question: "What is the total profit if sales increase by 20 percent?" If you set up your worksheet model properly, you can change the value in one cell to see what happens to the profit cell. The examples in this chapter take the opposite approach. If you know what a formula result should be, Excel can tell you the values that you need to enter in one or more input cells to produce that result. In other words, you can ask a question such as "How much do sales need to increase to produce a profit of $1.2 million?" Excel provides two tools that are relevant:

• Goal Seek: Determines the value that you need to enter in a single input cell to produce a result that you want in a dependent (formula) cell.

• Solver: Determines the values that you need to enter in multiple input cells to produce a result that you want. Moreover, because you can specify certain constraints to the problem, you gain significant problem-solving ...