Hi quick question: Does a line of best fit HAVE to be a straight line? because I have a set of data that look like they form a logarithmic function.

Attachment 27539

see, that does not look good. Any ideas or tips?!

Thanks for your time

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- Mar 15th 2013, 11:13 AMsakonpure6Line of Best Fit
Hi quick question: Does a line of best fit HAVE to be a straight line? because I have a set of data that look like they form a logarithmic function.

Attachment 27539

see, that does not look good. Any ideas or tips?!

Thanks for your time - Mar 15th 2013, 11:51 AMHallsofIvyRe: Line of Best Fit
Yes, a

**line**of best fit has to be a**line**which is just a short way of saying**straight**line. All lines are straight! - Mar 15th 2013, 12:05 PMsakonpure6Re: Line of Best Fit
:) thank you.

- Mar 15th 2013, 04:07 PMProve ItRe: Line of Best Fit
Yes, your line of best fit does have to be a line. HOWEVER, since your data looks logarithmic, then a logarithmic transformation to the data would be appropriate to make your data linear.

Note that the model might be appropriate. If we let , this gives , a LINEAR function.

So what you can do is to evaluate for each of your observed x values, and then do a least squares linear regression on the two sets and . Your model will then be much more accurate, and then it can be written in terms of again.