If it's a geometric sequence then:

We calculate the fourth and fifth term of the sequence:

Answer:
In year 4 15.1875 animals.
In year 5 11.390625 animals.
Here is the equation: (gas=g)
8.5g= 23.94
All you need to do is the inverse of multiplication on the other side. (division)
23.94/8.5= 2.81647.....
g= 2.82 (rounded to the hundredths place)
I hope this helps!
~kaikers
Angles B and D are supplementary angles, so if B's angle is 30 degrees, then D's angle at y would be 150, since they have to add to 180.
In short, angle y = 150