EXAMPLE 5Discrete probability distribution as a graph
The number of points a soccer team gets for a game is a random variable because it is not certain, before the game, how many points the team will get.
In Major League Soccer (MLS), teams are awarded 3 points in the standings for a win, 1 point for a tie, and 0 points for a loss. In the 34-game 2013 MLS season, the New York Red Bulls had 17 wins, 9 losses, and 8 ties.
Solution
The probabilities in Table 2 were assigned to the random variable using the relative frequency (empirical) method.
0 | 1 | 3 | |
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Given a graph of a probability distribution, you should know how to construct the probability distribution table, and vice versa.
NOW YOU CAN DO
Exercises 17b–24b.