An electronic instrument, weighing \(1000 \mathrm{~N}\), is supported on a rubber mounting whose forcedeflection relationship is given by \(F(x)=157 x+0.2 x^{3}\), where the force \((F)\) and the deflection \((x)\) are in newtons and millimeters, respectively. Determine the following:

a. Equivalent linear spring constant of the mounting at its static equilibrium position.

b. Deflection of the mounting corresponding to the equivalent linear spring constant.