00:01
So in this problem, we need to go back to a previous problem and make a residual plot for the least squares model.
00:09
So the previous problem was dealing with the weight of a car and miles per gallon.
00:15
Now remember, a residual plot is a way to identify that a linear regression model is actually a good fit.
00:21
So what i need to do is i need to do a residual plot.
00:26
So here's what i like to do.
00:28
If you're able to use technology, desmos .com.
00:32
So i'm just do the plus sign, and then i'm going to enter the information in.
00:37
So the x values from the problem, and then i'm going to pause the video and enter it.
00:50
And then when i come back, it'll all be entered.
00:56
So i've entered the information in, x1 are my x values, y1 are the y values.
01:01
Now i can't see them on my graph, so i could play around with my screen a little bit, and i could see that i have a decreasing situation.
01:09
So it appears the heavier the car.
01:12
No, yes, x value is the weight of the car, and y value are miles per gallon.
01:23
So the heavier car, the less miles per gallon.
01:27
Now to get a regression model using desmos, it's a little tricky.
01:31
I need to let my computer know i'm using y, subscript 1.
01:34
So that's y, shift underscore, which is right next to the plus sign on the top.
01:40
One...