First, plot the data shown as points.
The points are (0,0), (1.4, 10), (2.8, 20), (4.2, 30), (4.9, 35), (5.8, 40), and (8, 45).
The graph shows a proportional part (a straight line) and a curvy part. So, the limit of proportionality is shown at the end of the straight line segment. The image below shows this limit.
The gradient of the straight-line portion refers to the slope. Let's use the points (1.4, 10) and (2.8, 20).
Therefore, the gradient is 7.14.
The Young modulus formula is
Let's use the greater force and the greater extension.
Therefore, Young Modulus is 1.6x10^11.