Edexcel S2 2021 October — Question 5

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2021
SessionOctober
TopicDiscrete Random Variables
TypeSampling distribution of mean or linear combination

  1. A bag contains a large number of counters.
40\% of the counters are numbered 1
\(35 \%\) of the counters are numbered 2
\(25 \%\) of the counters are numbered 3 In a game Alif draws two counters at random from the bag. His score is 4 times the number on the first counter minus 2 times the number on the second counter.
  1. Show that Alif gets a score of 8 with probability 0.0875
  2. Find the sampling distribution of Alif's score.
  3. Calculate Alif's expected score.