Answer:
 x = 6.58 m
Explanation:
For this exercise let's use the concept of conservation of mechanical energy. Let's look for energy at two points the highest and when the spring is compressed
Initial
  Em₀ = U = m g and
Final
  [tex]E_{mf}[/tex] = ke = ½ k x2
As there is no friction the mechanical energy is conserved
  Em₀ = [tex]E_{mf}[/tex]
   m g y = ½ k x²
Let's use trigonometry to face height
   sin θ = y / L
   y = L sin θ
   x = √ 2mg (L synth) / k
   x = √ (2 11.8 9.8 2.17 sin35.6 / 3.11 104)
   x = 6.58 m