The Line of Best Fit ...?

[DragonCub]

Hei guys, I have a little doubt with A-level Chemistry Paper 5. Usually there is a part which asks for a graph plotted according to given data and the line of best fit is required.
I'm not sure if the line of best fit can sometimes be a curve to show certain relationships... What do you think?

 

[Kmax]

no its never a curve... its always a line which approximately shows the general trend of values

 

[Amy Bloom]

No. It's simply a line which passes through the majority of your plotted points, never a curve.

 

[Xenon]

Hei guys, I have a little doubt with A-level Chemistry Paper 5. Usually there is a part which asks for a graph plotted according to given data and the line of best fit is required.
I'm not sure if the line of best fit can sometimes be a curve to show certain relationships... What do you think?

well most of the time, it is a line but yes there can be a curve...like check the graph of the paper
http://www.xtremepapers.com/CIE/International A And AS Level/9701 - Chemistry/9701_s11_qp_52.pdf
and then the mark scheme: http://www.xtremepapers.com/CIE/International A And AS Level/9701 - Chemistry/9701_s11_ms_52.pdf

I'll quote the main thing:
Line of best fit (the correct graph is a curve, hence straight lines
gain zero. If however a wrong set of results genuinely produces a
straight-line, award the mark for a straight-line) (ignore
extrapolation at temperatures lower than 20 oC)

well that was not the first time a curve was expected to be drawn, as far as I remember there has been two such incidents of such including this one. I don't remember the other paper