The body of a 1258 kg car is supported on a frame by four springs. The spring constant of a single spring is 1?

The body of a 1258 kg car is supported on a frame by four springs. The spring constant of a single spring is 1.25 104 N/m. Four people riding in the car have a combined m of 291 kg. When driven over a pothole in the road, the frame vibrates and for the first few seconds the vibration approximates simple harmonic motion. What is the period of vibration of the car?