I've been teaching A Level maths for a few years and have never been stumped by a question like this one before.
It is from a Level 3 (A Level standard) Engineering Maths paper (Design and Mechtronic Engineering).
First part is easy, 2nd part, I haven't got a clue what it is wanting, even when I've been through the mark scheme.
a) Friction and Load are connected by F=aL+b, where a and b are constants to be determined, when F=100, L=70. When F=80, L=50.
b) Confirm your values for a and b, by plotting a graph where a and b are values to be determined.
The axis given for (b) have 'a' on the x axis from 0-1.4 and F on the y-axis from 0-140.
100 points for anyone who can guess what they are expecting for part b!