 In this video, I'm going to show you how to work with the Hubble data file. The first step of this process is making sure that you've downloaded the file from Blackboard. You guys are going to be working with the subset 1, but I'm going to step you through everything in the process using the subset 2. That way I don't give away the results. When you have this downloaded on your computer, if you've got Microsoft Excel, it should automatically recognize this comma separated values file as something that can be opened with Excel. Just in case it doesn't, normally if you right click on something, you can open with and specify which type of program you want to open it. In this case, I've got both Excel and LibreOffice, but this is the video for Excel. When you open up a file in Excel, it's going to warn you that this is not an Excel format file. It's a comma separated value file. In order to save everything you might want to do, you want to click go ahead and click save as. That's going to give you a chance to save it, not as a comma separated value, but as an Excel workbook. When it pulls up this menu on the save as rather than doing the standard what it already is, make sure you click the Excel workbook. In this case I had already created one, so I could maybe put in my name there to make sure it's got a different file name. Once you have that done, you'll notice that the warning message went away and it is actually an Excel file. The first thing we're going to want to do is to create a plot of this various pieces of information. In order to do that, you want to select the comments for distance and velocity. And you can do that by highlighting up here in the very top columns B and C. And you notice it selects the whole column and not just the stuff up there at the top. Once those are done, you want to insert a graph. So you come over here to the insert menu and then it's got lots of different options. Depending on exactly which version of Excel you have, it might look a little different. But what you're looking for is the scatter plot. When we click on that scatter plot, you want to choose just the regular scatter dots. And the first thing I'm going to do is make this just a little bit bigger so it's easier for me to see some things. The next thing that we're going to do is we're going to actually add some chart elements here to make it easier to interpret our data. And in Excel, you'll come over here to the add chart elements. Or up here, there's an add chart elements. Some of the things that we're going to add include axis titles. And for now, it's got a placeholder for those things. And for the grid lines, it may only have some of these. But if you come over here to the menu, we want to grab all of them. So under grid lines, go ahead and grab all of them. Now I'm going to go ahead and change my titles. And remember that the x was the distance. And that's in units of megaparsec. So you just change this title to be that quantity. Similarly over here, you're going to want to put in that this was the velocity. And that was in kilometers per second. And for the title of our graph, this was our Hubble's law. I've got to type the right key here. Now from this graph, you can answer a few of the questions in the lab. But what we really want to do is we want to fit a line to this so that we can use that line to help us estimate and understand our data. So we come back over here to the add chart elements. And we want to do a trend line. But don't just click here, click on the button over to the side, which is going to open up more options. So select the trend line, more options. When it does that, we can choose what type of line and we do want linear. But we want to set the intercept to be zero. And we want to display the equation on the chart. Now to make it easier for yourself to be able to see that line, we can come over here to the fill and line and just select a brighter color. And we can also make that line a little bit thicker in order to be able to see everything better. This is your best fit trend line that you're going to use to answer several of the questions in your lab report. For the equations, it moved my equation over here, but I'm going to move it over here where I can just see things a little bit better. And I'm going to just increase the size a little bit. You don't have to do that. It just makes it a little easier for us to talk about everything. For this equation, remember that our x was distance and our y was velocity. So in your lab report where it gives you the template v equals and then there's a space to put a number in. And then d, this is the number that you would put in. Well, not exactly, this is the number for subset two. When you do your analysis of subset one, you'll have a slightly different number in here. You'll take that number and put that into your lab report. That equation is then going to let you answer the rest of the questions for Hubble's law. If you have any difficulties on doing any of these steps, please get in touch with me. And of course, the last step that we need to do is to come over here to file and save now that you've created your graph because you're going to need to submit this new spreadsheet file back to me for grading. Again, if you have any questions, feel free to get in touch with me.