Question

Triangle ABC is similar to Triangle XYZ. 

Answer 1

XZ = 186.8625.

Since the triangles are similar, the ratio of their angles is the same.  This means the ratio of BC to YZ will be the same as the ratio of AC to XZ; using this to set up a proportion,

9.6/118.8 = 15.1/x

Cross multiply:
9.6*x = 118.8(15.1)
9.6x = 1793.88

Divide both sides by 9.6:
9.6x/9.6 = 1793.88/9.6
x = 186.8625