Answer:
The approximate  spring constant is  [tex]k = 55533.33 \ N/m[/tex]
Explanation:
From the question we are told that
  The  mass of the person is  [tex]m = 68 \ kg[/tex]
   The  dip of the car is  [tex]x = 1.2 \ cm = 0.012 \ m[/tex]
Generally according to hooks law Â
    [tex]F = k * x[/tex]
here the force F is the weight of the person which is mathematically represented as
     [tex]F = m * g[/tex]
=> Â Â [tex]m * g = k * x[/tex]
=> Â Â [tex]k = \frac{m * g }{x }[/tex]
=> Â Â [tex]k = \frac{68 * 9.8}{ 0.012}[/tex]
=> Â [tex]k = 55533.33 \ N/m[/tex]