EXAMPLE 16 Addition Rule

Continuing with the RMS Titanic data from Example 15, Table 6 is reproduced here. Find the probability that a randomly chosen passenger or crew member had the following characteristics:

  1. Was female
  2. Survived
  3. Was female and survived
  4. Was female or survived
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Solution

  1. Here, we seek . There were 470 female passengers and crew among the 2201 people on board the Titanic. Therefore, .
  2. We are looking for . Of the 2201 people on board the Titanic, 711 survived. Thus, .
  3. Those who were female and survived represent the intersection . In Example 15, we found that these were represented by the green cell with 344 people in it, lying in the intersection of the Female column and the Survived row. Therefore, .
  4. Here, we seek ( or ). By the Addition Rule,

NOW YOU CAN DO

Exercises 19–44.