Edexcel FS2 2021 June — Question 3

Exam BoardEdexcel
ModuleFS2 (Further Statistics 2)
Year2021
SessionJune
TopicCumulative distribution functions
TypeCalculate probabilities from CDF

  1. The continuous random variable \(X\) has cumulative distribution function given by
$$\mathrm { F } ( x ) = \left\{ \begin{array} { c r } 0 & x < 2
1.25 - \frac { 2.5 } { x } & 2 \leqslant x \leqslant 10
1 & x > 10 \end{array} \right.$$
  1. Find \(\mathrm { P } ( \{ X < 5 \} \cup \{ X > 8 \} )\)
  2. Find the median of \(X\).
  3. Find \(\mathrm { E } \left( X ^ { 2 } \right)\)
    1. Sketch the probability density function of \(X\).
    2. Describe the skewness of the distribution of \(X\).