I originally attempted to submit this post in reply about 20 hours ago, and then again about 3 hours ago, and it never appeared.

I removed the hyperlink to another page, and it worked, so I have left out the hyperlink...

Thank you Antonitsin, however I am trying to work out the stats to modify my visual basic program. It needs to run independently of any other program. Thank you anyway though.

Thanks Dragan for your help too.

Sorry for my ignorance, but is YBar and XBar1 simply the mean of Y and the mean of X1? I assume so, but thought I'd check.

That looks quite straightforward... is that the case for calculating b1, b2, b3, etc?

Thanks Dason for your help.

I read through that link you posted and the page on the bottom re simple linear regression, but find it extremely confusing.

The way I have been doing linear regression is via the following formula...

Y' = YMean + r(Sy/Sx)(X-Xmean)

where r = pearson correlation coefficient,

Sy and Sx are the standard deviations of Y and X.

or using the raw score equivilant:

Y' =YMean + (NΣXY-(ΣX)(ΣY)/NΣX²-(ΣX)²)(X-XMean)

(sorry for the messiness of that btw)

This is from an old book I've got - "Fundamentals of Behavioral Statistics, sixth edition".

These equations I am very familiar and comfortable with.

looking at the equation in your link under the heading "Estimation methods", Ordinary Least Squares:

made some sense, except for the ' character... which I then read

**"denotes the transpose, so that xi′β is the inner product between vectors xi and β."**
Hmm, my brain's hurting at this stage...especially as its after midnight here...

I was hoping it would be more straight forward to understand, but I suspect I'm off to learn, as Spunky inferred, matrix algebra...

I did find one page that dealt with 2 dependent variables.

As stated elsewhere, I think in your link, Dason, the equation is UGLY.

The page gives the following information:

To find b1, the equation is:

to find b2, the equation is:

and to find a, the equation is:

can I extend these equations to 3 or more?

If so, is it difficult?

a would be easy, i assume, ie for 3 dependent variables, should be:

**a = YMean - b1XMean1 - b2Xmean2 - b3XMean3**
b1, b2, b3 etc looks more complicated but I'd guess something along the lines of:

ΣX)²

b1 = ((Σx3²)(Σx2²)(Σx1y)-(Σx1x2x3)(Σx2y)(Σx3y)) / ((Σx1²)(Σx2²)(Σx3²)-(Σx1x2x3)²)

That is however, just a guess looking at it, late at night, and could be completely wrong...

Would it be easier to to learn matrix algebra than trying to extend these equations, given I may need to use up to 5 dependent variables?

Thanks again for your help and any advice you can give.

Josh