Edexcel FS2 Specimen — Question 1

Exam BoardEdexcel
ModuleFS2 (Further Statistics 2)
SessionSpecimen
TopicCumulative distribution functions
TypeDistribution of order statistics

  1. The three independent random variables \(A , B\) and \(C\) each have a continuous uniform distribution over the interval \([ 0,5 ]\).
    1. Find the probability that \(A , B\) and \(C\) are all greater than 3
    The random variable \(Y\) represents the maximum value of \(A , B\) and \(C\).
    The cumulative distribution function of \(Y\) is $$\mathrm { F } ( y ) = \begin{cases} 0 & y < 0
    \frac { y ^ { 3 } } { 125 } & 0 \leqslant y \leqslant 5
    1 & y > 5 \end{cases}$$
  2. Using algebraic integration, show that \(\operatorname { Var } ( Y ) = 0.9375\)
  3. Find the mode of \(Y\), giving a reason for your answer.
  4. Describe the skewness of the distribution of \(Y\). Give a reason for your answer.
  5. Find the value of \(k\) such that \(\mathrm { P } ( k < Y < 2 k ) = 0.189\)