AQA AS Paper 2 2022 June — Question 15

Exam BoardAQA
ModuleAS Paper 2 (AS Paper 2)
Year2022
SessionJune
TopicDiscrete Probability Distributions
TypePiecewise or conditional probability function

15 The discrete random variable \(X\) is modelled by the probability distribution defined by: $$\mathrm { P } ( X = x ) = \left\{ \begin{array} { c c } c x & x = 1,2
k x ^ { 2 } & x = 3,4
0 & \text { otherwise } \end{array} \right.$$ where \(k\) and \(c\) are constants.
15
  1. State, in terms of \(k\), the probability that \(X = 3\)
    15
  2. Given that \(\mathrm { P } ( X \geq 3 ) = 3 \times \mathrm { P } ( X \leq 2 )\)
    Find the exact value of \(k\) and the exact value of \(c\).
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