This is a simple harmonic motion problem. A simple Harmonic motion can be defined as special type of periodic oscillation where the restoring force is directly proportional to the displacement. The restoring force then acts in the direction opposite to the displacement.
All simple harmonic motion is sinusoidal.
PERIOD is the time required to complete a full cycle.
From the question, the period of position change of an object attached to a spring is 4.4 s. There are two potential energy and two kinetic energy maxima per period, therefore, we have 4.4/2 = 2.2 s.
