It is given that when C = 20, the value of L is 124.942, whereas when C = 110, the value of L is 125.134.
Accordingly, points (20, 124.942) and (110, 125.134) satisfy the linear relation between L and C. Now, assuming C along the x-axis and L along the y-axis, we have two points i.e., (20, 124.942) and (110, 125.134) in the XY plane.
Therefore, the linear relation between L and C is the equation of the line passing through points (20, 124.942) and (110, 125.134).
\((L - 124.942) =\frac{125.134-124.942}{110-20}(c-20)\)
\(L-124.942=\frac{0.192}{90}(c-20)\)
i.e,\(L=\frac{0.192}{90}(c-20)+124.942\), which is the required linear relation.