(a)[2]
Show that $\text{P}(X = 2) = 0.114$ as required.
(b)[3]
Fill in the probability distribution table for $X$.
(c)[3]
Determine the value of $\operatorname{Var}(X)$.
Mathematics 9709 · AS & A Level · Discrete random variables
Discrete random variables — practice question
Anil is competing in a tournament. In each match of this tournament, a player earns $2$ points for a win, $1$ point for a draw and $0$ points for a loss. For any of Anil’s games, the probabilities that he will win, draw or lose are $0.5$, $0.3$ and $0.2$ respectively. The outcomes of the games are mutually independent. The random variable $X$ represents the total number of points that Anil obtains from his first $3$ games in the tournament.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Gives the correct outcomes for $P(X=2)$ and formulates the probability expression.” …
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