A machine supported symmetrically on 4 springs and has a mass of 90 kg. Reciprocating mass is 2 kg having a vertical stroke of 100 mm with SHM. Determine the stiffness of each spring (in N/mm) so that force transmitted to the foundation is \(\frac{1}{15}^{th}\)  of the impressed force. The machine rotates at 800 rpm. (Round if to two decimal places)