A microphone is attached to a spring that is suspended from the ceiling. Directly below on the floor is a stationary 412-hertz source of sound. The microphone vibrates up and down in simple harmonic motion with a period of 1.9s. The difference between the maximum and minimum sound frequencies detected by the microphone is 1.8 hertz. Ignoring any reflections of sound in the room and using 343 m/s for the speed of sound, determine the amplitude of the simple harmonic motion.