Edexcel S1 2015 June — Question 6

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2015
SessionJune
TopicNormal Distribution
TypeMultiple probability calculations

  1. The random variable \(Z \sim \mathrm {~N} ( 0,1 )\)
    \(A\) is the event \(Z > 1.1\)
    \(B\) is the event \(Z > - 1.9\)
    \(C\) is the event \(- 1.5 < Z < 1.5\)
    1. Find
      1. \(\mathrm { P } ( A )\)
      2. \(\mathrm { P } ( B )\)
      3. \(\mathrm { P } ( C )\)
      4. \(\mathrm { P } ( A \cup C )\)
    The random variable \(X\) has a normal distribution with mean 21 and standard deviation 5
  2. Find the value of \(w\) such that \(\mathrm { P } ( X > w \mid X > 28 ) = 0.625\)