Rat pregnancies only last for 21 days. One group of scientists monitored a small population of rats for several months. At the beginning of the experiment, there were 8 rats. By the end of the experiment, the students observed a population growth rate of 12.5% every month. This rat situation can be modeled by an exponential function. Gross, right?

A) What was the initial value of the rat population?

Initial value =

B) What is the rat population growth rate (the percentage)? Remember this is NOT the base ‘b,’ but it does impact the value of ‘b.’

Growth Rate, r, as a percentage =

C) What is the growth factor (the value of b) of the rat population?

Growth Factor, b =

D) Write the exponential model (equation) that best describes this rat population. Use the ^ symbol to represent a raised exponent.