Edexcel S2 2010 January — Question 4

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2010
SessionJanuary
TopicContinuous Probability Distributions and Random Variables
TypeFind or specify CDF

  1. The continuous random variable \(X\) has probability density function \(\mathrm { f } ( x )\) given by
$$f ( x ) = \begin{cases} k \left( x ^ { 2 } - 2 x + 2 \right) & 0 < x \leqslant 3
3 k & 3 < x \leqslant 4
0 & \text { otherwise } \end{cases}$$ where \(k\) is a constant.
  1. Show that \(k = \frac { 1 } { 9 }\)
  2. Find the cumulative distribution function \(\mathrm { F } ( x )\).
  3. Find the mean of \(X\).
  4. Show that the median of \(X\) lies between \(x = 2.6\) and \(x = 2.7\)