AQA AS Paper 1 2020 June — Question 10

Exam BoardAQA
ModuleAS Paper 1 (AS Paper 1)
Year2020
SessionJune
TopicExponential Equations & Modelling

10 Raj is investigating how the price, \(P\) pounds, of a brilliant-cut diamond ring is related to the weight, \(C\) carats, of the diamond. He believes that they are connected by a formula $$P = a C ^ { n }$$ where \(a\) and \(n\) are constants.
10
  1. Express \(\ln P\) in terms of \(\ln C\).
    10
  2. Raj researches the price of three brilliant-cut diamond rings on a website with the following results.
    \(\boldsymbol { C }\)0.601.151.50
    \(\boldsymbol { P }\)49512001720
    10
    1. Plot \(\ln P\) against \(\ln C\) for the three rings on the grid below.
      \includegraphics[max width=\textwidth, alt={}, center]{091aecd0-d812-4a8f-8596-a1c91f3bae1c-15_1018_1467_751_283} 10
  3. (ii) Explain which feature of the plot suggests that Raj's belief may be correct.
    10
  4. (iii) Using the graph on page 15 , estimate the value of \(a\) and the value of \(n\). 10
  5. Explain the significance of \(a\) in this context.
    10
  6. Raj wants to buy a ring with a brilliant-cut diamond of weight 2 carats. Estimate the price of such a ring.