An ornithologist decides to track the population of American goldfinches in her neighborhood. In 2011, she observes that there are 4 goldfinches in her neighborhood. In 2021, she records that there are 16 goldfinches. Let be the number of goldfinches in the neighborhood years after 2011. a) Assuming the goldfinch population is growing linearly, find a formula for .

Interpret the slope of in the context of the problem.





b) Assuming the goldfinch population is growing exponentially, find a formula for .

Interpret the growth rate of in the context of the problem.





Hint: