 In this previous video, we built this simple decision model about a newspaper vendor and the decisions he could make on how to maximize his profit. And by playing around with the model, as you saw, we can put in values of Q, the decision variable that he can make, and the profit will change based on that value. But is there a way we could let Excel help us find a particular goal? And the answer is yes, we can use a tool in Excel called GoldSeek. We go up to the data tab, look for what if analysis, because that's what we're doing, what if here, and click on GoldSeek. And we bring up this little dialog box. I'm going to take that cell, clear it out, and click on my profit and say I want to see how many papers I should buy Q to get a profit of $225. Whoops, I didn't do that right. $225. And I'm going to do it by changing the cell here, the purchase quantity. And we just click OK. And we get an answer. In order to get a profit of $225, he needs to buy a total of 4,500 papers, which seems kind of odd because he has to buy a surplus in order to get that particular value. But it can be useful. GoldSeek gives you the ability to just check on one variable at a time and one outcome at a time. There's another tool we'll show later that allows you to take into account more than one variable at a time and try to get an optimum value. But anyway, GoldSeek is a useful tool, and I will show you how to keep track of what the outcomes are shortly.