Question

What is the meaning of extrapolation with an example? How would I "not extrapolate" points given when plotting a graph?

Answer 1

This question would probably be better answered in the math group.

When you have some data points and you have come up with the equation of a line of best fit, you can use that line in two different ways. You can use it to infer the value of the data *between* the points used to generate the line, which is called interpolation. Or you can use it to infer the value of the data in the domain *outside* the measured points, which is *extrapolation*.

Hope that helps, and if you'd like a mathematician to answer rather than a biologist, please post it in math.

Answer 2

Ok, so I can't see the numbers in your picture. But what you should do is plot the data you have. Then draw a line of best fit through it. Extend the line into the range you don't have data for but want to make inferences about. Use it to make estimates at that point.

Answer 3

Sorry about that, and yes I did that. I also drew the line of best fit, but what would I have done for my line to have been called extrapolated?

Answer 4

In the answer it says "Credit line of best fit – no extrapolation
Joins point to point no extrapolation beyond first and last point"
Would i not extend the line beyond those points??

Answer 5

Yes, when it says "no extrapolation" it means don't draw the lines beyond the first and last points. Interpolate by connecting the points with lines, don't extrapolate by drawing lines beyond them.

Answer 6

Ohhhhhhh. So would i have to connect the first and last points?

Answer 7

Or would i simply draw the line of best fit within?

Answer 8

I'm not entirely sure. It either wants you to draw different lines between the points - literally just connect the dots - or draw a line which seems to describe the data fairly well, but does not necessary pass through all (or indeed, even any) of the points.

Answer 9

I think the second option applies here pretty well. Thanks for the help!