 In this video, I'm going to explain to you how to construct your XY data pairs so that you can make the plot that shows the frequency magnitude distribution of these earthquakes. So let's go back to the spreadsheet here. I've got my table of values that shows all the magnitudes of the earthquakes that happened in 1975 in the New Madrid region, and I have them sorted in descending order so that the largest magnitude earthquake is up here in spot number one, and the lowest one is down here in spot number 183, and that's the total number of earthquakes that there were in 1975 that were recorded. Now, I've made a second table of values over here, and there's one column called magnitude and one column that says number of earthquakes greater than or equal to that magnitude. And these are going to end up being the X and Y values of the plot that I'm going to make. And we're going to get these X and Y values by doing some manipulation of the original data over here. So my X values, I've already just stuck them in. They should go from the largest magnitude by increments of 0.1, so you can see that, right, down to the lowest magnitude that you have in your catalog. And my lowest magnitude is 1.0, so there that is. And now we want to find at each magnitude how many earthquakes are there in the catalog that have that magnitude or higher magnitude. That's why we sorted these earthquakes, so it would be easier to figure that out. Okay, so let's go back to the catalog and start with that. So the largest is 4.3, and how many are there of those? There's just the one. So one, easy. Okay, now, this is the part where you have to think just a little bit. The next earthquake down from 4.3 is 3.3, and there's three of those, right? So what we want to do is write down the number of earthquakes that are at least magnitude 3.3 in this catalog. And there are four of those, right? Because there's this 3.3, this one, this one, and the 4.3. All of those earthquakes are 3.3 or greater. Now, what we can see is that the actual number corresponding to the last 3.3 magnitude earthquake is the number we're looking for, right? So, over here to our XY table, find 3.3 and write in a 4. Now, what do we do with these blank spots up here? Well, let's just think about it. How many earthquakes are at least magnitude 3.4 in this catalog? Well, there's just one. There's just the 4.3 that's larger or equal to 3.4, right? So there's just one. And now I hope you can see that you could fill in a one in each one of these boxes as well. In fact, you have to. That's correct. Okay. All right, so let's go back to our catalog now and go to the next earthquake down. The next magnitude down is 2.8, and there's two of them. So we can see that there are six earthquakes in this catalog, at least as large as magnitude 2.8. So let's go over here now and we write 6. And we fill in the blank ones above 2.8 in this row with 4s, using the same logic that we used to fill in the ones above magnitude 3.3, right? Okay, let's go back to our catalog. Here's 2.7. There's just one of those. This is easy. So we read off a 7 right there. Hopefully you can see the pattern now. There's two of these. There's nine earthquakes in the catalog that are at least magnitude 2.5 or greater, so that means there's a nine here. And that means above that, where there's a blank spot we put in a 7, there's at least 10 earthquakes in the catalog whose magnitude is, sorry, there are exactly 10 earthquakes in the catalog whose magnitude is at least 2.4, that's a 10 here. There are exactly 20 earthquakes in this catalog whose magnitude is at least 2.3, and I think you can do the rest of this by hand yourself.