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Tips on drawing a best fit line?

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So today we did a lab on melting points of fatty acids and we have to draw a best fit line for the graph. This counts for marks, but I suck at drawing best fit lines.. Help! 

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Hey,

 

I'm assuming you have a bunch of points on your graph, and you're meaning to represent the pattern (of the graph; so is it increasing, decreasing, etc.) with a line of best fit.

 

You want to basically draw your line through all of the points (not necessarily connect them; well unless it's linear), and draw the line in the direction your data points to (increasing, decreasing, etc.).

 

It's hard to explain, but these pictures should give you an idea:

 

https://www.google.ca/search?q=line+of+best+fit&biw=1366&bih=667&source=lnms&tbm=isch&sa=X&ei=PKlqVKruE4ilyASSgoHQCg&sqi=2&ved=0CAYQ_AUoAQ#facrc=_&imgdii=_&imgrc=jZ-8I-tHRKGfWM%253A%3BwFBnwF93-KABRM%3Bhttp%253A%252F%252Fwww.mathsisfun.com%252Fdata%252Fimages%252Fscatter-ice-cream1a.gif%3Bhttp%253A%252F%252Fwww.mathsisfun.com%252Fdefinitions%252Fline-of-best-fit.html%3B453%3B278

 

https://www.google.ca/search?q=line+of+best+fit&biw=1366&bih=667&source=lnms&tbm=isch&sa=X&ei=PKlqVKruE4ilyASSgoHQCg&sqi=2&ved=0CAYQ_AUoAQ#facrc=_&imgdii=_&imgrc=Ozkh3Z35yPhO5M%253A%3BxhsLeBqE09YFMM%3Bhttp%253A%252F%252Fstaff.argyll.epsb.ca%252Fjreed%252Fmath9%252Fstrand4%252Fpizza2.jpg%3Bhttp%253A%252F%252Fstaff.argyll.epsb.ca%252Fjreed%252Fmath9%252Fstrand4%252F4104.htm%3B637%3B528

 

Hopefully that was of some use.

Edited by Mathemagician
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If you have a TI N-spire, or similar calculator, you can enter in the data points and do a linear regression. It'll give you the 'least squares line' - and will luckily tell you what the equation actually is! 

 

For example: https://epsstore.ti.com/OA_HTML/csksxvm.jsp?nSetId=108059

The equation it gives you is y=ax+b, where the calculator gives you a and b.

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If you have to hand draw it, do it lightly with pencil, when you think you have it right go over it darker and erase any unnecessary lines that make the graph messy.

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Also, i figure checking out a few examples help

 

http://www.mathsisfun.com/definitions/line-of-best-fit.html

http://www.glogster.com/haleybelt/line-of-best-fit/g-6n0hhq97n3deh5bbndah8bt

Here are a couple of them that I found, for linear examples

 

http://terpconnect.umd.edu/~toh/spectrum/CurveFitting.html

http://www.york.ac.uk/physics/people/tallents/l11809/

And here are a couple for curves

 

Just remember to scroll down the website to find them

hope i helped

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