what form chap 3 of core

[tcstudent]

hello, im bit confused when it comes to linear regression, if the question does not ask for y=mx+c or y=a+bx which one do i use?

[McFleurry]

They are the same.
c=a (y-int)
m=b (gradient)
Doesn't matter the way you write it, as long as it's right.

[tcstudent]

thanks, but when you do
y=mx+c eg y=2x+5
or
y=a+bx
y=5+2x

it appears differently so im just confused and ive got a test tomorrow so im trying to get it right before its too late,

[McFleurry]

okay: just make them the same (ie rearrange them )
so, as a=c, put them on the end.

Thus, you have,
1) for y=ax+c
y=2x+5
2) for y=mx+b
y=2x+5

Compare the two. Same, yes?
Good luck with the test

[Yacoubb]

Typically the following is used:

* Least Squares Regression Line. y=a +bx
* Three-Median Regression Line   y= mx + c

It isn't really a fixated rule; just ensure that you are aware of the slope & intercept of the regression model when it comes to determining and/or interpreting these statistical values in further analysis.

[Zealous]

Typically the following is used:

* Least Squares Regression Line. y=a +bx
* Three-Median Regression Line   y= mx + c

It isn't really a fixated rule; just ensure that you are aware of the slope & intercept of the regression model when it comes to determining and/or interpreting these statistical values in further analysis.

Well both are exactly the same, with just the y intercept and gradient represented with different pro-numerals. I didn't think that "typically" you use a + bx for least squares and mx + c for three median, I've just used whatever I'm comfortable with (which I see more of mx + c due to methods).

Just make sure you can interpret the y intercept and the gradient.
You may get questions like:

fare = a + b x maximum distance

and you are required to find a and b, so you need to recognise in this case that a is the y intercept and b is the slope/gradient.

And you may get it the other way round:

fare = a x maximum distance + b

So you just need to be able to identify which one is the slope and what is the y intercept and sub in appropriate values.

[Yacoubb]

Well both are exactly the same, with just the y intercept and gradient represented with different pro-numerals. I didn't think that "typically" you use a + bx for least squares and mx + c for three median, I've just used whatever I'm comfortable with (which I see more of mx + c due to methods).

Just make sure you can interpret the y intercept and the gradient.
You may get questions like:

fare = a + b x maximum distance

Yeah I know.. I just said typically when a regression model is described in each of the ways, that is the typical format. I KNOW that they are the same and I mentioned that

and you are required to find a and b, so you need to recognise in this case that a is the y intercept and b is the slope/gradient.

And you may get it the other way round:

fare = a x maximum distance + b

So you just need to be able to identify which one is the slope and what is the y intercept and sub in appropriate values.