Recent content by ianripping

Sorry if you are getting bored of me - I still can't extend my method to get the a 3rd degree polynomial. Could someone look back at my example and possibly help me move this on? Thanks

An example I found: Example Find the least squares quadratic of best fit for the following data. x 1 2 3 4 y 1 2 2 2 Sum of n = 4 Sum of x = 10 Sum of x^2 = 30 Sum of x^3 = 100 Sum of x^4 = 354 Sum of y = 7 Sum of xy = 19 Sum of x^2 = 59 so.. 4a + 10b + 30c =7 10a + 30b + 100c = 19 30a + 100b...

The above example makes perfect sense for determining a straight regression line. I can't see how to expand this to get a quadratic or even 3rd or 4th degree polynomial regression line.

So if i were doing this for 2nd degree, where would my C coefficient come from?

Sorry, I am really confused by this - without any examples with data sets I just can't get my head round it.

I just don't understand how I plug the numbers in. I don't remember how the sigma sign works. Could you show me how you get to the first linear equation?

Can anyone help me with this?

Hi, I am really sorry. I am not following. I don't quite understand the equations. Could you put my given data set into one of these 4 equations ans show me the working? Thanks

Wow, it has been a while sine I have done my A-Level Statistics. Could you help me up to the point of solving the 4 linear equations? Could you show me an example / point to a link that shows how to get to the point of having the 4 linear equations? Thanks

Hi. I know how to find the coefficients of a quadratic with a data set using least sqaures. I now would like to do with to find a polynomial to the 3rd and 4th term. Could someone help me with this? The data set I am using: (-4.5,0.7) (-3.2,2.3) (-1.4,3.8) (0.8,5) (2.5,5.5)...