Rational numbers are sometimes natural numbers.
Answer:
See below
Step-by-step explanation:
1. 12
2. 15 [3*12-21 = 15]
3. 24 [3*15-21 = 24]
4. 51 [3*24 - 21 = 51]
from 2007 to 2012 is only 5 years, so we can see this as a compound interest with a rate of 1.2% per annum for 5 years, so

Siny/2.7=sin63/2.8
siny=2.7sin63/2.8
y=arcsin((2.7sin63)/2.8)
y≈59.23° (to nearest one-hundredth of a degree)