 In this part, we're being asked to calculate the total sales for each agent, each representative in each region. We want the sum of their sales in these regions. So we're going to click in that cell, click equal, and put SUM, there are a number of sums there. I'm just going to talk about the first three. The first one is the sum. It just adds all the numbers and a range of sales. Well, we're more complicated than that. SUMIF adds the sales that were specified by a given single condition. Here we've got two conditions, two criteria. So we need the SUMIFs, which allow us to find our sums based on two criteria. So I'm going to double click that to enter it, and it says, first of all, the SUM range. What are we adding up? Well, we want to add up the sales. I'm going to click over here in G2, and then drag down to the bottom, to the bottom, to the bottom, to the bottom. Where's my bottom? There it is. So now I've got my SUM, I put a comma. The first one that says it's criteria range one. And we're going to do the region first. So I'm going to go over here and select cell C2, drag it down to get the region. Go back up there. If you remember, we're going to be locking down these things. So I'm going to go ahead and lock down, hit the F4, F4, let me go ahead and lock down my sales dollars as well. Whoops. You notice if you cycle through your F4, it'll go from no dollar signs to both dollar signs to just the row, to just the column, to no. So I'm going to go back to lock everything down, and then lock the other one down there. Okay, put my comma, and now we want the criteria for the region, and that's going to be in this cell, K16. And remember, here we're going to lock down the row so we can drag it across. So I put my insertion in front of the 15 and hit the single dollar sign to lock that down. Put a comma. Now the next is my criteria range for my sales rip, and that's going to be over here starting at D2, drag it down to get all my sales rips, names. And again, we want to lock that down. So I'm going to put my insertion key there, hit F4 to lock down the beginning cell, insert in the second cell, F4 to lock down the ending cell. Put a comma, and now I need my criteria, and that's going to be over here with Charlie to start. And remember, here we want to make sure that we stay in the J column as we copy across. So I put my insertion point in front of the J, put a single dollar sign there, close out with a closing parentheses, hit Enter, and there's my sales for Charlie, and because I've locked everything down, I can drag it down to get the sales for all of the salesmen in the Middle East, and then get my plus sign and drag it over, and I've got my sales for all of the salesmen for all of the regions, and let's just go ahead and format that. I'm going to highlight that, and then I'm going to click dollar signs to give dollars there, and I'm going to click on decrease decimal just so we see the dollars. So there's the answer.