ASTM C $39/$C $39$M $($see the note below$)$ prescribes a standard for conducting compression test on concrete cylinders. On page $4,$ it gives a correction factor to be multiplied with the measured compression strength. Correction factor is given for selective L$/$D ratios $($length$/$diameter$).$ Suppose you tested a cylinder with length $L=8"$ and $D=5",$ determine the correction factor by interpolation using a Lagrange polynomial of order $1$ and $2.$ Which estimate do you you think is more accurate?