Edexcel S1 2007 January — Question 3

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2007
SessionJanuary
TopicDiscrete Probability Distributions
TypeConstruct probability distribution from scenario

  1. The random variable \(X\) has probability function
$$\mathrm { P } ( X = x ) = \frac { ( 2 x - 1 ) } { 36 } \quad x = 1,2,3,4,5,6$$
  1. Construct a table giving the probability distribution of \(X\). Find
  2. \(\mathrm { P } ( 2 < X \leqslant 5 )\),
  3. the exact value of \(\mathrm { E } ( X )\).
  4. Show that \(\operatorname { Var } ( X ) = 1.97\) to 3 significant figures.
  5. Find \(\operatorname { Var } ( 2 - 3 X )\).