Edexcel S1 2023 June — Question 6

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2023
SessionJune
TopicConditional Probability
TypeDice/random device selects population

6\% of the counters labelled C are red
One counter is selected at random from the bag.
  1. Complete the tree diagram on the opposite page to illustrate this information.
  2. Calculate the probability that the counter is labelled A and is not red.
  3. Calculate the probability that the counter is red.
  4. Given that the counter is red, find the probability that it is labelled C \end{enumerate} \includegraphics[max width=\textwidth, alt={}, center]{b8ac20db-4237-4def-81aa-a3eecbeefbdd-15_1155_1000_285_456}
    5. A discrete random variable \(Y\) has probability function $$\mathrm { P } ( \mathrm { Y } = \mathrm { y } ) = \left\{ \begin{array} { c l } \mathrm { k } ( 3 - \mathrm { y } ) & y = 1,2
    \mathrm { k } \left( \mathrm { y } ^ { 2 } - 8 \right) & y = 3,4,5
    \mathrm { k } & y = 6
    0 & \text { otherwise } \end{array} \right.$$ where \(k\) is a constant.
  5. Show that \(k = \frac { 1 } { 30 }\) Find the exact value of
  6. \(\mathrm { P } ( 1 < Y \leqslant 4 )\)
  7. \(\mathrm { E } ( Y )\) The random variable \(X = 15 - 2 Y\)
  8. Calculate \(\mathrm { P } ( Y \geqslant X )\)
  9. Calculate \(\operatorname { Var } ( X )\)
    1. Three events \(A , B\) and \(C\) are such that
    $$\mathrm { P } ( A ) = 0.1 \quad \mathrm { P } ( B \mid A ) = 0.3 \quad \mathrm { P } ( A \cup B ) = 0.25 \quad \mathrm { P } ( C ) = 0.5$$ Given that \(A\) and \(C\) are mutually exclusive
  10. find \(\mathrm { P } ( A \cup C )\)
  11. Show that \(\mathrm { P } ( B ) = 0.18\) Given also that \(B\) and \(C\) are independent,
  12. draw a Venn diagram to represent the events \(A , B\) and \(C\) and the probabilities associated with each region.