1. The problem statement, all variables and given/known data I am given a table of data derived from experiment. A force (F) is applied to a spring and the extension (x) is measured and recorded. An additional column of data for the derivative (dF/dx) is also provided. Here is the data: x(m) F(kN) df/dx (kN/m) 0.0 0.0 5.0 0.03 0.3 10.2 0.06 0.5 4.3 0.12 0.7 5.2 0.2 1.8 8.2 0.22 1.9 1.1 The task is: using a difference approximation ( I think this is either backward, forward or central difference approximation), estimate the numerical value of the derivative dF/dx at x=0.16 based on the values provided in the table. 2. Relevant equations None given 3. The attempt at a solution None so far. Since I don't know how to go about it. I know the solution to this must be very simple, but it just won't filter into my brain.