OCR S3 2009 June — Question 1

Exam BoardOCR
ModuleS3 (Statistics 3)
Year2009
SessionJune
TopicContinuous Probability Distributions and Random Variables
TypeFind expectation E(X)

1 A continuous random variable \(X\) has probability density function given by $$f ( x ) = \begin{cases} \frac { 2 x } { 5 } & 0 \leqslant x \leqslant 1
\frac { 2 } { 5 \sqrt { x } } & 1 < x \leqslant 4
0 & \text { otherwise } \end{cases}$$ Find
  1. \(\mathrm { E } ( X )\),
  2. \(\mathrm { P } ( X \geqslant \mathrm { E } ( X ) )\).