To solve this problem it is necessary to apply the concepts related to Period in a spring, elastic potential energy and energy in simple harmonic movement.
From the definition we know that the period can be expressed as

Where
m= Mass
k = Spring constant
Our values are given as
m = 16.6Kg
K = 2470N/m
Therefore the period would be



PART A) The frequency is the inverse of the period therefore

PART B) Elastic potential energy depends on compression and elasticity therefore



PART C) Kinetic energy depends on mass and speed therefore

PART D) As energy is conserved, the total energy is equivalent to the dual ratio of the elasticity constant and the amplitude, mathematically,




Therefore the motion's amplitude is 1.07m