Check Answers please (Exponential Functions)

Question:

The population of the state of New New York is given by an exponential function R=R(b) which has the formula

$\displaystyle R = 15 * 1.08^b$

R is measured in millions, b is time measured in years since 1990.

1. What is the population in 1990?

$\displaystyle R(0) = 15 million$

2. What is the yearly growth factor for R?

$\displaystyle \begin{array}{|c|c|c|c|} 0 & 1 & 2 & 3\\

\hline

15&16.2&17.49&18.89\\

\end{array}$

The yearly growth factor is 1.08. ($\displaystyle 16.2/15 = 1.08$ & $\displaystyle 17.49/16.2 = 1.08$)

3. What is yearly percentage growth rate for R?

Growth Rate is 1.08; yearly growth percentage is 1.08 - 1 = .08 = 8%

4. What is monthly percentage growth rate for R?

Since yearly growth is .08, .08 / 12 would be .006, so about .6% per month

Thanks in advance!