Answer :
you can set up the ratio 12.4:18.6 because it says that the parallelograms are similar.
now simplify as much as possible
12.4:18.6
6.2:9.3
2:3
now simplify as much as possible
12.4:18.6
6.2:9.3
2:3
the ratio of y: z is
12.4: 18.6,
since the issue is the parallelogram 1 (y) and parallelogram 2 (z)
12.4: 18.6,
since the issue is the parallelogram 1 (y) and parallelogram 2 (z)