Hi, folks. We're working on problem number 18. Number 18 gives us some information and asks us to perform a linear regression on the data. And I've been to take a look at the graph and to talk about it a little bit. Um, so the charts that they give us has three columns in it, and we have to take a second and say, What are we really looking at here? What are we entering? What are we using? Right when we enter this into a graphing utility, Um, the months 1234 those air. Not really What you need to be looking at. Those were just apparently randomly selected months. That's what it's described in the paragraph. Um, they do label, however, as X and y the advertising expenditures and the sales volume. That's actually what you want to type in to your columns. So don't do the month Thio. Start with the advertising expenditures and then do the sales volume. I have entered that over here in this calculator, and you could see how the information is set up. I'm gonna go out and perform my linear aggression right now so I can take a look at it. Okay, so here I choose linear regression. And in this one, I'm going to type C one because that's the cattle. That's the column that I've entered this information into. Right, So see one And the next one? That's not the one. That's a cue. See one and we'll get it. Here, Alfa load C one. There you go. On N C two. So Alfa Mood C two and then right here. It says, What do you want us to do with the equation? I want you to put it into the graph for so we can look at it that we won't have to re type it myself s. So I go ahead and select Why one and it's gonna put it in Y one, and we should be ready to run the regression, right? Well, these air our numbers in the UNR ound ID form. Okay, Um, let's go ahead and write those down here on the next page. Okay, so I got these two things written down. I got the correlation coefficient again from the calculator. It just says CEO har um And then there's the equation itself. And I did that by taking the A value in the B value and rounding them and putting them into the equation. Okay, so that's what the second part a and part B ask for. Okay, so now we need Thio. Look at both of them in the same window and interpret the slope of this model in the context of this will be fun. Okay, so we had this entered it, put it into the graph for for us because of that middle thing that I pressed and we should be able to take a look at the graph were zoomed in a weird level. If you ever get a graph, it looks like this. You can use my favorite zoom data number nine, and it should re center it essentially right simply Alright, What we've got here is the line that the calculator came up with and the data points that we plotted. Um, now, if you look at this, it pretty much conforms to align. It's not exact, it's not, But it is actually kind of sort of like that stretched out a lot of information, so it's pretty close. What they're asking to do, though, is to think about the slope of that line. What does that mean? What really What it means is that means as you spend more money on advertising, you get more revenue, right? So it's how quickly and at what rate that your expenditures get to turn into, you know, more sales. So let's go ahead and put that on the on the answer sheet on this page. Okay, So the way that I phrased it was the slope is representing the rate in which the advertising expenditures increase total sales. Okay. And I like to put rate in there because, really, that's that's what slopes are. All right. And then the last part D it asked us to use the model toe, figure out a number for if we spend $1500 on advertising. So we're gonna go ahead and put that in for the expenditures, which is X, and then we're going to run it through our equation. We're going to see what happens. Okay, so what we do is we substitute this in for X, and then we go ahead and run it through. I like thio. Use the if I have already entered the information in a graphing utility or calculator. Um, you could just look up. What number? Here's the X value. 1.5. And there's what? My result waas. Okay, that saves a little bit of time there, Um, does the math for you? In fact, you've already done the math just by, you know, entering in the calculator. So one important thing here, why did I put 1.5 and 1500 right? Didn't say $1500. Well, if you look at the original data, the original data was in thousands of dollars. Okay, so 1.5 would be in thousands of dollars. Okay, Now the sales volume, right? They never tell us what that is. What about what the volume is? Maybe it's units. Maybe it's I don't know. We don't know what it is. So we're not gonna have any units on this one. But this is for 1500. Okay. Uh huh. All right. Thank you.