CAIE S1 2014 June — Question 4

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2014
SessionJune
TopicHypergeometric Distribution
TypeCalculate variance given expectation

4 A book club sends 6 paperback and 2 hardback books to Mrs Hunt. She chooses 4 of these books at random to take with her on holiday. The random variable \(X\) represents the number of paperback books she chooses.
  1. Show that the probability that she chooses exactly 2 paperback books is \(\frac { 3 } { 14 }\).
  2. Draw up the probability distribution table for \(X\).
  3. You are given that \(\mathrm { E } ( X ) = 3\). Find \(\operatorname { Var } ( X )\).