AQA Further Paper 3 Statistics 2019 June — Question 5

Exam BoardAQA
ModuleFurther Paper 3 Statistics (Further Paper 3 Statistics)
Year2019
SessionJune
TopicContinuous Probability Distributions and Random Variables
TypeFind parameter from median

5 An insurance company models the claims it pays out in pounds \(( \pounds )\) with a random variable \(X\) which has probability density function $$f ( x ) = \begin{cases} \frac { k } { x } & 1 < x < a
0 & \text { otherwise } \end{cases}$$ 5
  1. The median claim is \(\pounds 200\)
    Show that \(k = \frac { 1 } { 2 \ln 200 }\)
    5
  2. Find \(\mathrm { P } ( X < 2000 )\), giving your answer to three significant figures.
    5
  3. The insurance company finds that the maximum possible claim is \(\pounds 2000\) and they decide to refine their probability density function. Suggest how this could be done.