Year 12s: what will be the first way you research your future options? >>

s1

Question 4 part iv on this:
The mark scheme says the value of r is larger. Why is this??
https://pmt.physicsandmathstutor.com/download/Maths/A-level/S1/Papers-OCR/January%202010%20QP%20-%20S1%20OCR.pdf

Reply 1

Pangol

Original post by Chelsea12345

I think you mean question 3, not 4.

Look at the scatter diagram.As it stands, the best straight line through these points in not great - there is a lot of scatter around that line. (I know the line is not drawn, but however you imagine drawing this line, there are going to be some points that are quite a long way from it.)

You can identify which point they are talking about removing. If you draw the best straight line through the remaining points, the degree of scatter around this line is less that it was originally. r can be interpreted as a measure of how much scatter there is - if r is +1 or -1, there is no scatter at all. The closser r is to 0, the larger the amount of scatter.

So, in this case, what would be the consequence for r of removing that point?