Edexcel S2 2006 January — Question 5

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2006
SessionJanuary
TopicContinuous Probability Distributions and Random Variables
TypeFind median or percentiles

5. A continuous random variable \(X\) has probability density function \(\mathrm { f } ( x )\) where $$f ( x ) = \begin{cases} k x ( x - 2 ) , & 2 \leq x \leq 3
0 , & \text { otherwise } \end{cases}$$ where \(k\) is a positive constant.
  1. Show that \(k = \frac { 3 } { 4 }\). Find
  2. \(\mathrm { E } ( X )\),
  3. the cumulative distribution function \(\mathrm { F } ( x )\).
  4. Show that the median value of \(X\) lies between 2.70 and 2.75.