Edexcel S2 2014 June — Question 6

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2014
SessionJune
TopicCumulative distribution functions
TypePDF to CDF derivation

6. The continuous random variable \(X\) has probability density function \(\mathrm { f } ( x )\) given by $$f ( x ) = \left\{ \begin{array} { c c } \frac { 2 x } { 9 } & 0 \leqslant x \leqslant 1
\frac { 2 } { 9 } & 1 < x < 4
\frac { 2 } { 3 } - \frac { x } { 9 } & 4 \leqslant x \leqslant 6
0 & \text { otherwise } \end{array} \right.$$
  1. Find \(\mathrm { E } ( X )\).
  2. Find the cumulative distribution function \(\mathrm { F } ( x )\) for all values of \(x\).
  3. Find the median of \(X\).
  4. Describe the skewness. Give a reason for your answer.
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