2024 CGSS P1 Q11

2024 CGSS P1 Q11

9 marks

After \(n\) years, the population, \(P\), in thousands, of a certain species of foxes can be modelled by an equation \(P = A\mathrm{e}^{kn}\), where \(A\) and \(k\) are constants.

The table below shows the values of \(n\) and \(P\).

\(n\)

\(5\)

\(10\)

\(15\)

\(20\)

\(25\)

\(P\)

\(6.23\)

\(4.85\)

\(3.78\)

\(2.94\)

\(2.29\)

  1. On the grid on the next page, plot \(\ln P\) against \(n\) and draw a straight line graph.[2]
  2. Use your graph to estimate the initial population of the foxes and the value of \(k\).[4]
  3. If this model for the population remains valid, after how many whole years would the population of the foxes first decreased to \(1000\)?

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs a course plan.

Answer:(a) \(\ln P\approx2.08-0.050n\). (b) Initial population approximately \(8000\) foxes; \(k\approx-0.050\). (c) \(42\) whole years.

Need help? Join our A-Maths tuition classes.

Learn more