Edexcel FS1 AS Specimen — Question 2

Exam BoardEdexcel
ModuleFS1 AS (Further Statistics 1 AS)
SessionSpecimen
TopicDiscrete Random Variables
TypeFunctions of random variables

  1. The discrete random variable \(X\) has probability distribution given by
\(x\)- 10123
\(P ( X = x )\)\(c\)\(a\)\(a\)\(b\)\(c\)
The random variable \(Y = 2 - 5 X\)
Given that \(\mathrm { E } ( \mathrm { Y } ) = - 4\) and \(\mathrm { P } ( \mathrm { Y } \geqslant - 3 ) = 0.45\)
  1. find the probability distribution of X . Given also that \(\mathrm { E } \left( \mathrm { Y } ^ { 2 } \right) = 75\)
  2. find the exact value of \(\operatorname { Var } ( \mathrm { X } )\)
  3. Find \(\mathrm { P } ( \mathrm { Y } > \mathrm { X } )\) \section*{Q uestion 2 continued}