|MadSci Network: Physics|
A best fit line is used to connect a set of coordinates on a graph in a way that allows us to see a relationship clearly. It is basically a "best estimate" of what a line would look like if all the data points fell on it. Why don't data points always fit? Because measurement is never a perfect thing. There is always a margin of error in whatever we measure. If you cook, for instance, and the recipe requires one cup of milk, I bet it's seldom that you use precisely that amount - you fill the cup up to about the one cup line and go for it. Data are like that too. In measuring the speed of an object, the position of a particle, the length of an organism, there's always a little uncertainty. Best fit allows us to take these uncertainties into account, and give us a start on refining the data for more accuracy. To see a very simple and practical example of best fit and how it works, go to http:// www.saburchill.com/physics/chapters/0073.html Thanks for a great question.
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