The given formula is:
Where t is measured in years since 2001 and n(t) is measured in millions.
a. What was the rat population in 2001?
Since t is measured in years since 2001, then we need to subtract 2001 from the year we want to analyze. So:
By replacing t=0 into the formula we obtain:
As n(t) is measured in millions, thus, the rat population in 2001 was 66000000 rats.
b. What does the model predict the rat population was in the year 2020?
t in the year 2020 is:
Then:
In the year 2020 the predicted rat population was 87764294 rats.