Regression Line

[delta7]

For the data sets, find the regression line without using a calculator

1. x 1245
y1334

2. x135
y247

I honestly have no clue. I missed this class

I do konw that I have to use y=mx + b, that's all I know.

 

[galactus]

It would appear you are given two sets of data points: (1245,1334) and (135,247)

First, find the slope. Then, use y=mx+b to find the line equation.

Here is an example. Follow this lead.

Suppose we had (4,9) and (-5,12)

The slope is the difference is the y values divided by the difference in the x values.

\(\displaystyle m=\frac{12-9}{-5-4}=\frac{3}{-9}=\frac{-1}{3}\)

Now, we can choose either set of points to plug into y=mx+b for x and y and solve for b.

\(\displaystyle 9=\frac{-1}{3}(4)+b\)

\(\displaystyle b=\frac{31}{3}\). b is where it crosses the y -axis.

There is the line equation for those two example points, \(\displaystyle y=\frac{-1}{3}x+\frac{31}{3}\)

Now, use this method for your points and you got it. Let me know what you get.

BTW, this is not calculus. I am moving the topic to beginning algebra.

 

[mmm4444bot]

… I honestly have no clue. I missed this class …

I regret that you missed your class; however, the message boards here are (in general) not an online classroom. Most of us who volunteer at this site want to see evidence of some comprehension before we tutor.

You may, of course, choose to wait and see if a volunteer will type up a lecture for you, but you might be waiting for awhile. I'm not going to type up any lessons for you because these lessons already exist all over the Internet.

I found THIS ONE using Google keywords linear, regression, and calculus.

If you read your textbook lessons and examples, and you cannot relate that information to your two given exercises, then you need to be able to form specific questions for us, so that we might determine WHERE to begin helping you.

Is there something specific about your textbook that you do not understand about regression?

 

[mmm4444bot]

Hi Cody:

I read the post as two exercises, each involving a set of four data points, with the objective of using regression to get the line of best-fit.

In other words, in (1) we have the points (1,1) (2,3) (4,3) and (5,4).

I leave it for the original poster to confirm or clarify.

~ Mark

 

[delta7]

That is correct, it is 4 data points and not two. Would I do it in the same manner?

 

[mmm4444bot]

… Would I do it in the same manner?

If you're going to do the regression by hand, then it involves slopes of more than a single line.

Did you look at the reference material at the link I posted?

If there is anything that you do not understand about the EXAMPLES there, then please ask SPECIFIC questions.

If you do not like what you see at that site, then use Google to find a site that you are willing to work with.

Is there something wrong with your textbook?

 

[delta7]

Ok, I will check it out, thanks so much for your help, i'll let you know how it goes.

 

[galactus]

You mean x1245 is meant to be x=1,2,4,5?.

With that kind of posting no wonder I got confused. :roll:

 

[mmm4444bot]

You mean x1245 is meant to be x=1,2,4,5? I'm afraid so. :|

Well, actually there is a space missing there.

x 1245 is meant to be x = {1, 2, 4, 5}.

x135 is meant to be x = {x, 1, 3, 5}. In other words, the second exercise involves a symbolic regression (oh, heck, I guess I'm not actually sure about the second exercise.)

With that kind of posting no wonder I got confused. There is certainly no shortage of submissions on these boards that constitute riddles! (I wish it were not so because I have a very low tolerance for preventable wasted time.)

MY EDITS: Corrected grammatical error, and added comment about x-space versus x-no-space notation.

 

[galactus]

Yes, indeed, mmm. One does not have to be very math savvy to have a little common sense.