Question

each percent is an annual interest rate. in the formula y=a*b^x what value would you use for b?
3.7%

Answer 1

3.7% means 3.7 per cent, or: 3.7/100 = 0.0037.
You start with 100%, so after one year you have 103.7% = 103.7/100=1.0037.
So b=1.0037 is your growth rate.