Edexcel S1 2018 June — Question 1

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2018
SessionJune
TopicCumulative distribution functions
TypeDiscrete CDF to PMF

  1. The discrete random variable \(X\) has the following probability distribution
\(x\)24710
\(\mathrm { P } ( X = x )\)\(a\)\(b\)0.1\(c\)
where \(a , b\) and \(c\) are probabilities.
The cumulative distribution function of \(X\) is \(\mathrm { F } ( x )\) and \(\mathrm { F } ( 3 ) = 0.2\) and \(\mathrm { F } ( 6 ) = 0.8\)
  1. Find the value of \(a\), the value of \(b\) and the value of \(c\).
  2. Write down the value of \(\mathrm { F } ( 7 )\).