 In the last module, you learned two ways to get a regression equation you can use to do predictions and forecasts. One was doing a scatter plot, and on the scatter plot, adding a trend line and the regression equation as I have here. The other way was to do a full regression using the data analysis regression tool to get the intercept and month coefficients, the intercept and slope coefficients. And both of those are right, except that you need to be aware of what your instructor might be grading for. If you use the equation off of the trend line, be aware that these values for the intercept and the slope are rounded, and so you'll get slightly different values for your forecast than you would get if you use the more precise intercept value and slope value from the regression. Now I'll show you how that works. I'm going to start using the trend equation, and to get our forecast, we just click on the cell we want, click equal, I want my intercept, and because I want to drag this down through all the month, I'm going to go ahead and hit function for F4 on the windows to lock that cell, plus the slope, and I want to lock that again, function F4 times the x value that we're interested in. It hit enter, and we get a value there that looks pretty good, and of course, because we've locked that down, we can get our prediction cross and drag this down all the way to get our forecast. Using your regression equations is similar. Hit equal, and I'm going to get my intercept, lock that down with F4, plus my slope, lock that down times my x value, and get enter. And you can see there's a little bit of difference there. This is 129237.31, 129238.96. So if you have time to run the regression, the full regression, I would use those values because they're a little more accurate. On the other hand, we're forecasting, and there's a lot of unknowns in forecasting, so using the values from the trend line would not be that bad. There are two other ways that you can easily get the more accurate regression line values, and that's using a forecast function, and it's equal FOR, I start typing, and you get a number of forecast functions. Now we're not going to use these first five there. Those are a little more complex, and we'll get into that a little bit later in this module. Right now we're going to use the older forecast function. We're going to use that basic forecast when we need to enter our x value again, which would be that month, put a comma, and then our known y's. So I'm going to select my y's and drag down to make sure I've got them all selected. I need to put a comma in my known x's, and I'm ready to go, except I want to lock down the ranges so that I can drag it down again. I'm going to put my cursor in that first value, hit F4, second value F4, whoops, want to get double dollar size, and there's a little trick there. You can actually select the range into F4 and get them both done at the same time. Put my closing parentheses and enter, and I've got a value there, which is the same. If I expand those, you'll see that they're exactly the same value. The final way I want to show you is using the trend function, and it's equal trend, and it's very similar to the cast function. You give it the known y's, which will be, again, starting there, comma, my known x's, comma, then you need your new x's. And the reason this has new x's, you can use the trend function as an array tool, which is a little more complex, so I'm just going to show you the basic. We're just going to go with one x there, and we're going to ignore the last part, the constant, and close it off. And again, if I want to drag it down, I need to lock those ranges down, hit enter, and I get exactly the same value, and you can see I can drag these down to get my forecast.