Question

The graph below shows two different deer populations over the same ten year period.

Deer Population
mc026-1.jpg

Which of the following answers is the best description for the deer population with the greatest growth rate:
The blue line shows a deer population that grew with an exponential growth rate. In the first year the population increased by only one deer, but between years seven and eight the population grew by two deer, showing that the growth rate continuously doubles.
The blue line shows a deer population that grew with a linear growth rate, because the graph shows that the population increased by approximately one deer per year.
The red line shows a linear growth rate, because an approximate straight line estimates a growth rate of five deer per year.
The red line demonstrates an exponential growth rate, because the growth rate for the deer population is itself continuously increasing.

Answer 1

The red line demonstrates an exponential growth rate, because its increase accelerates over time (the amount added each year gets larger). The other choices are incorrect: the blue line is roughly linear (≈1 deer/yr), and the blue/exponential and red/linear descriptions are not supported by the graph.