Edexcel S1 2024 January — Question 6

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2024
SessionJanuary
TopicProbability Definitions
TypeCombined event algebra

  1. The events \(A\) and \(B\) satisfy
$$\mathrm { P } ( A ) = x \quad \mathrm { P } ( B ) = y \quad \mathrm { P } ( A \cup B ) = 0.65 \quad \mathrm { P } ( B \mid A ) = 0.3$$
  1. Show that $$14 x + 20 y = 13$$ The events \(B\) and \(C\) are mutually exclusive such that $$\mathrm { P } ( B \cup C ) = 0.85 \quad \mathrm { P } ( C ) = \frac { 1 } { 2 } x + y$$
    1. Find a second equation in \(x\) and \(y\)
    2. Hence find the value of \(x\) and the value of \(y\)
  2. Determine whether or not \(A\) and \(B\) are statistically independent. You must show your working clearly.