Thanks. You are right. This has now been corrected.
Posted on 7th June 2017
In the two extension questions only 5 values are given, whereas the original data set has 6 values. Given the provided solutions, I think this is actually an error and so extra x_6 and y_6 need to be added to the questions.
Posted on 5th June 2017
An excellent resource for my core maths group.
Posted on 11th September 2016
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